Aerosol generating devices, aerosol generating articles, and aerosol delivery systems

Abstract

The aerosol generating device (100) is configured for use in heating an aerosol-generating (200) article to generate an inhalable aerosol from an aerosol-forming substrate of the aerosol-generating article. The aerosol generating device comprises a housing (101). The housing (101) comprises a cavity (105) configured to receive the aerosol-generating article (200). The housing (101) is adapted to define a cooling airflow path extending from an exterior of the housing (101), through an interior of the housing (101), to an air-permeable portion of a wall (106) of the cavity (105). The wall (106) of the cavity (105) is tubular. The air-permeable portion of the wall of the cavity comprises at least one annular air-permeable band (112). The annular air-permeable band (112) is configured to direct airflow radially from the cooling airflow path into the cavity (105) around a periphery of the tubular wall (106) of the cavity (105).

Description

[Technical Field]

[0001] The present disclosure relates to aerosol generating devices, aerosol-generating articles for use with aerosol generating devices, and aerosol delivery systems formed from both the aerosol generating device and the aerosol-generating articles. [Background technology]

[0002] Aerosol-generating devices configured to generate an aerosol from an aerosol-forming substrate, such as a tobacco-containing substrate, are known in the art. These known devices may generate an aerosol from the substrate by application of heat to the substrate rather than by combustion of the substrate. The aerosol-forming substrate may be present as a component of an aerosol-generating article, where the aerosol-generating article is physically separate from the aerosol-generating device. During use, the aerosol-generating device may be received by the aerosol-generating article. The device may provide electrical power to enable the transfer of heat from a heat source to the aerosol-forming substrate of the aerosol-generating article. During use of these known aerosol-generating devices and aerosol-generating articles, volatile compounds are released from the aerosol-forming substrate by heat transfer from the heat source and are entrained in the air drawn through the aerosol-generating article. As the released compounds cool, they condense to form an aerosol, which is inhaled by the consumer. The transfer of heat to the aerosol-forming substrate to generate the aerosol can result in the aerosol emitted from the aerosol-forming substrate having a very high temperature, with the substrate being known in some known aerosol-generating articles to reach temperatures of about 270° C. when heated. Known aerosol-generating articles can require a complex arrangement of different components downstream of the substrate to cool the substrate to a level sufficient to avoid burns to the user's mouth or throat. Summary of the Invention

[0003] The present disclosure is concerned with providing improvements in airflow management for aerosol generating devices and aerosol-generating articles.

[0004] According to a first aspect of the present disclosure, there is provided an aerosol generating device configured for use in heating an aerosol-generating article to generate an inhalable aerosol from an aerosol-forming substrate of the aerosol-generating article. The aerosol generating device comprises a housing having a cavity configured to receive the aerosol-generating article. The housing is adapted to define a cooling airflow path extending from an exterior of the housing, through an interior of the housing, to an air-permeable portion of a wall of the cavity.

[0005] Ambient air outside the device housing is likely to be cooler than inside the housing when the device is operating. Therefore, having a housing that defines a cooling airflow path extending from the outside of the housing provides a readily available source of ambient cooling air during use of the device. Providing a breathable portion in the wall of the cavity may allow the inflow of ambient cooling air received from outside the device to be directed into the interior of the cavity via the cooling airflow path. This may provide the beneficial effect of cooling the interior of the cavity. Furthermore, when the aerosol-generating device is used in combination with an aerosol-generating article docked within the cavity, the cooling air received via the breathable portion of the wall of the cavity may be used to cool specific portions of the aerosol-generating article.

[0006] The aerosol-generating device is preferably configured, in use with an aerosol-generating article docked within the cavity, such that the air-permeable portions of the walls of the cavity mate with corresponding air-permeable portions of the exterior wall of the aerosol-generating article. Matching the air-permeable portions of the walls of the aerosol-generating device cavity with the exterior wall of the aerosol-generating article allows for efficient channeling of airflow from the device's cooling airflow path into the interior of the aerosol-generating article.

[0007] As used herein, the term "breathable" is used in reference to an entity that allows air to pass through. The term "breathable" also encompasses the volumetric properties of a suitable material, for example, a material that has porosity throughout all or a portion of the material's volume, in reference to either all or a portion of its volume.

[0008] As used herein, the term "match" is used to mean exact or partial overlap.

[0009] As used herein, the term "aerosol-generating device" is used to describe a device that interacts with the aerosol-forming substrate of an aerosol-generating article to generate an aerosol. The aerosol-generating device is preferably a smoking device that interacts with the aerosol-forming substrate of the aerosol-generating article to generate an aerosol that is inhalable directly through the user's mouth into the user's lungs. The aerosol-generating device may also be a holder for a smoking article.

[0010] Preferably, the aerosol-generating article is a smoking article that generates an aerosol that is inhalable directly through the user's mouth into the user's lungs. More preferably, the aerosol-generating article is a smoking article that generates a nicotine-containing aerosol that is inhalable directly through the user's mouth into the user's lungs.

[0011] As used herein, the term "aerosol-forming substrate" means a substrate made of or including an aerosol-forming material capable of releasing volatile compounds upon heating to generate an aerosol.

[0012] Advantageously, the wall of the cavity may be tubular. The cavity may be provided with an open end and a closed end. The aerosol-generating device may be configured to receive the aerosol-generating article through the open end of the tubular cavity. Providing the device with a tubular cavity is particularly appropriate when the device is intended to be used with an aerosol-generating article that defines a rod shape, and has a tubular shape of the cavity that corresponds to the geometric profile of such a rod. For example, if the aerosol-generating article is a smoking article, the use of a rod-shaped geometry in the article corresponds to the geometric shapes of known smoking articles such as conventional cigarettes and e-cigarettes.

[0013] As used herein, the term "rod" is used to mean a generally cylindrical element of substantially circular, oval, or elliptical cross section.

[0014] The breathable portion of the cavity wall may comprise one or more of a porous material, a plurality of slits, or a plurality of holes. By way of example and without limitation, the breathable portion of the cavity wall may be provided as a mesh, with gaps in the mesh defining openings therein, thereby providing permeability for airflow therethrough. Alternatively, the downstream end of the cooling airflow path may terminate in an open end free of any mesh or other restriction, the open end being the breathable portion of the cavity wall, directing cooling air from the cooling air path directly into the cavity. In a further alternative, the breathable portion of the cavity wall may comprise a plurality of voids, where the plurality of voids define voids within the wall material. The size of any voids, slits, or holes that may form part of the breathable portion of the cavity wall directly affects the permeability of the breathable portion to airflow. Therefore, the size of any such voids, slits, or holes may be selected according to the desired volumetric flow rate of cooling air within the cavity of the aerosol generating device.

[0015] As used herein, the terms "upstream" and "downstream" are used to describe the relative position of an element or portion of an element of a heated aerosol-generating article with respect to the direction in which a user draws on the aerosol-generating article during use of the aerosol-generating article.

[0016] Preferably, the cavity wall is tubular, and the breathable portion of the cavity wall comprises at least one annular breathable band. Providing the breathable portion of the cavity wall as one or more annular bands allows cooling air from the cooling airflow path to be directed radially into the cavity around the periphery of the tubular cavity wall. When the device is used with an aerosol-generating article docked within the cavity, and the outer wall of the aerosol-generating article has a corresponding breathable portion provided as an annular band, matching alignment of the annular band of the device with the annular band of the article may provide a uniform radial inflow of cooling air into the interior of the aerosol-generating article around the periphery of the outer wall of the article.

[0017] Advantageously, the at least one annular breathable zone may include a first annular breathable zone and a second annular breathable zone. The first and second zones may be axially spaced apart from one another along the longitudinal axis of the cavity and have distinct first and second permeabilities to airflow therethrough. Providing the first and second annular breathable zones with different permeabilities to airflow may enable correspondingly different flow rates through the first and second annular zones. This may in turn enable different levels of cooling to be achieved in different regions of the cavity.

[0018] Advantageously, the aerosol generating device may further comprise control electronics provided within the housing. The cooling airflow path may extend through or adjacent to the control electronics to provide cooling to the control electronics. In this way, cooling air from outside the housing may help to prevent overheating of the device's control electronics.

[0019] The aerosol generating device preferably does not include any fan or similar means for forcing a flow of air from outside the housing of the device along the cooling airflow path. Rather, the flow of air from outside the housing along the cooling airflow path is instead preferably driven by a user applying suction to the mouth end of an aerosol-generating article docked within the cavity of the device. These features are discussed in more detail below with respect to the second aspect of the present disclosure defining an aerosol delivery system. However, in an alternative embodiment, the aerosol generating device may be configured to force a flow of air from outside the housing toward a breathable portion of the wall of the cavity along the cooling airflow path. By way of example, the device may include an electric fan provided within the housing to drive the flow of air along the cooling airflow path, the fan being provided with power from a power source provided within the device.

[0020] Conveniently, the aerosol-generating device may be an electrical device for heating the aerosol-forming substrate of the aerosol-generating article by either or both induction and resistance heating. The device may include a power source for providing electrical power. The power source is preferably a battery, thereby providing the device with the advantage of portability. The battery is preferably a rechargeable battery.

[0021] In one embodiment of an induction heating version of the apparatus, the wall of the cavity may comprise a susceptor portion. The susceptor portion may be axially spaced apart from the air-permeable portion of the wall of the cavity along the longitudinal axis of the cavity. The aerosol-generating apparatus may further comprise an inductor coil surrounding the susceptor portion. Preferably, the inductor coil may surround the susceptor portion radially outward of the susceptor portion. Locating the inductor coil radially outward of the susceptor portion prevents damage to the inductor coil from contact with the aerosol-generating article during insertion of the article into the cavity. In use, power supplied to the inductor coil (e.g., by the aforementioned power supply of the apparatus) causes the inductor coil to induce eddy currents in the susceptor portion. These eddy currents in turn cause the susceptor portion of the wall of the cavity to generate heat. As described above, when an aerosol-generating article is docked in the cavity, heat generated within the cavity by the susceptor portion may be transferred to the article, heating the aerosol-forming substrate within the article to a temperature sufficient to cause an aerosol to emanate from the substrate. The susceptor portion is formed of a material capable of absorbing electromagnetic energy and converting it to heat. By way of example and without limitation, the susceptor portion may be formed of a ferromagnetic material such as steel.

[0022] In a variation of the inductively heated version of the apparatus outlined above, the cavity wall may lack any susceptor but still comprise an inductor coil surrounding the cavity wall. Preferably, the inductor coil may surround the cavity wall radially outward of the wall. Alternatively, the susceptor may be provided as part of the aerosol-generating article, and preferably may be wholly or partially enclosed within the aerosol-forming substrate of the aerosol-generating article.

[0023] In one embodiment of a resistively heated version of the device, the cavity may comprise a resistive heating element. The resistive heating element may be arranged to surround (in use) an aerosol-generating article docked in the cavity of the device. By way of example, the resistive heating element may have the form of an annular sleeve. The annular sleeve may be located within the wall of the cavity or may form part of the wall of the cavity. Alternatively, the resistive heating element may be arranged to be inserted (in use) within the interior of an aerosol-generating article docked in the cavity of the device, so as to be in close proximity to or in direct contact with the aerosol-forming substrate of the article. By way of example, the resistive heating element may have the form of a blade. In use, power is supplied to the resistive heating element (e.g., by the aforementioned power supply of the device), which causes the heating element to heat up.

[0024] According to a second aspect of the present disclosure, there is provided an aerosol delivery system comprising an aerosol-generating article and an aerosol-generating device. The aerosol-generating article defines a rod. The rod contains an aerosol-forming substrate. The rod's outer wall comprises a breathable portion. The breathable portion of the rod's outer wall is positioned downstream of the aerosol-forming substrate. The device and article are configured such that when the aerosol-generating article is docked in the cavity, the breathable portion of the cavity wall coincides with the breathable portion of the rod's outer wall. The aerosol-generating device may be as described above for any of the embodiments relating to the first aspect of the present disclosure.

[0025] In this second aspect of the disclosure, the matching alignment of the air-permeable portion of the cavity wall with the outer wall of the rod serves to facilitate efficient channeling of cooling air from the cooling airflow path of the device into the interior of the aerosol-generating article.

[0026] Preferably, the aerosol-forming substrate is a solid aerosol-forming substrate. However, the aerosol-forming substrate may comprise both solid and liquid components. Alternatively, the aerosol-forming substrate may be a liquid aerosol-forming substrate.

[0027] Preferably, the aerosol-forming substrate comprises nicotine. More preferably, the aerosol-forming substrate comprises tobacco. Alternatively, or additionally, the aerosol-forming substrate may comprise a non-tobacco-containing aerosol-forming material.

[0028] Where the aerosol-forming substrate is a solid aerosol-forming substrate, the solid aerosol-forming substrate may comprise, for example, one or more of powder, granules, pellets, shreds, threads, strips, or sheets containing one or more of herb leaves, tobacco leaves, tobacco stems, expanded tobacco, and homogenized tobacco.

[0029] Optionally, the solid aerosol-forming substrate may contain tobacco or non-tobacco volatile flavor compounds, which are released upon heating of the solid aerosol-forming substrate. The solid aerosol-forming substrate may also contain one or more capsules, for example containing additional tobacco or non-tobacco volatile flavor compounds, which may melt during heating of the solid aerosol-forming substrate.

[0030] Optionally, the solid aerosol-forming substrate may be provided on or embedded in a thermally stable carrier. The carrier may be in the form of a powder, granules, pellets, pieces, threads, strips, or a sheet. The solid aerosol-forming substrate may be deposited on the surface of the carrier in the form of, for example, a sheet, foam, gel, or slurry. The solid aerosol-forming substrate may be deposited on the entire surface of the carrier, or alternatively, may be deposited in a pattern to provide non-uniform flavor delivery during use.

[0031] In one preferred embodiment, the aerosol-forming substrate comprises a homogenized tobacco material. As used herein, the term "homogenized tobacco material" refers to a material formed by agglomerating particulate tobacco.

[0032] Preferably, the aerosol-forming substrate comprises an assembly of sheets of homogenized tobacco material. As used herein, the term "sheet" refers to a layered element having a width and length that is substantially greater than its thickness. As used herein, the term "assemblage" is used to describe a sheet that is rolled, folded, or otherwise compressed or constricted substantially transversely to the longitudinal axis of the aerosol-generating article.

[0033] Preferably, the aerosol-forming substrate comprises an aerosol former. As used herein, the term "aerosol former" is used to describe any suitable known compound or mixture of compounds that, in use, facilitates the formation of an aerosol and is generally resistant to thermal decomposition at the operating temperatures of the aerosol-generating article.

[0034] Suitable aerosol formers are well known in the art and include, but are not limited to, polyhydric alcohols (such as propylene glycol, 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.). Preferred aerosol formers are polyhydric alcohols or mixtures thereof (such as propylene glycol, triethylene glycol, 1,3-butanediol, and most preferably glycerin).

[0035] The aerosol-forming substrate may comprise a single aerosol former, or alternatively, the aerosol-forming substrate may comprise a combination of two or more aerosol formers.

[0036] Preferably, the aerosol-generating article may further include a first airflow path and a second airflow path. The rod has a mouth end and a distal end, the mouth end being located downstream of the distal end. The first airflow path may extend downstream toward the mouth end along the interior of the rod through the aerosol-forming substrate, such that upon application of suction at the mouth end, air is drawn into the aerosol-generating article and passes downstream toward the mouth end along the interior of the rod through the aerosol-forming substrate. The second airflow path may extend through an air-permeable portion of the outer wall of the rod when the article is docked in the cavity of the device, supplying the cooled airflow received from the cooled airflow path to a mixing region within the rod. The air-permeable portion and the mixing region may be located downstream of and immediately adjacent to the aerosol-forming substrate, such that, in use, the airflow along the second airflow path mixes with the aerosol flow along the first airflow path in the mixing region. By locating the breathable portion and the mixing region downstream of and immediately adjacent to the aerosol-forming substrate, the air received from the cooling airflow path of the device and flowing along the second airflow path can efficiently cool any hot aerosol gas emanating from the heating of the aerosol-forming substrate and flowing along the first airflow path. Locating the breathable portion and the mixing region downstream of and immediately adjacent to the aerosol-forming substrate may also ensure that the cooled air and the aerosol are efficiently mixed before reaching the mouth end of the rod. Efficient mixing of the cooled air and the aerosol within the rod of the aerosol-generating article is important in providing an enhanced experience to users of the system. This efficient mixing of the cooled air and the aerosol is in contrast to conventional ventilated cigarettes, which introduce air into the cigarette through perforations provided far from the aerosol-forming substrate at or very close to the mouth end of the cigarette. As a result, conventional ventilated cigarettes do not achieve complete and efficient mixing of the incoming ventilated air with the hot aerosol gas, which can result in a poor user experience.

[0037] Advantageously, the aerosol-forming substrate is located at the distal end or closer to the distal end than the oral end.

[0038] The interior of the rod is preferably free of obstacles from the mixing region to the mouth end, so that the mixed flow is not impeded when flowing from the mixing region to the mouth end during use. For example, the aerosol-generating article may lack a mouthpiece filter or aerosol-cooling element that obstructs the downstream flow path toward the mouth end, as commonly found in known electronic cigarettes. The lack of any such obstacles within the interior of the rod downstream of the aerosol-forming substrate may help reduce the drawing resistance of the first and second airflow paths and may also help reduce the amount of suction a user needs to apply at the mouth end to inhale a given amount of the mixed flow of aerosol and cooled air. Furthermore, this may also help reduce the complexity of manufacturing the aerosol-generating article.

[0039] The breathable portion of the rod's exterior wall may comprise one or more of a porous material, a plurality of slits, or a plurality of holes. By way of example and without limitation, the breathable portion of the rod's exterior wall may be provided as a mesh, with interstices in the mesh defining openings therein, thereby providing permeability for airflow through the mesh (i.e., through the exterior wall). In a further alternative, the breathable portion of the rod's exterior wall may comprise a plurality of voids, wherein the plurality of voids define voids in the material of the exterior wall. The size of any voids, slits, or holes that may form part of the breathable portion of the rod's exterior wall directly affects the permeability of the breathable portion to airflow. The size of any such voids, slits, or holes may be selected according to the desired volumetric flow rate of cooling air within the interior of the aerosol-generating article.

[0040] The outer wall of the rod may be provided as a wrapper, which surrounds the aerosol-forming substrate. For example, the wrapper may be cigarette paper. The wrapper may be provided with perforations to form breathable portions of the outer wall of the rod. The wrapper preferably has a thickness of approximately 0.02 to 0.07 millimeters, or approximately 0.03 to 0.05 millimeters. The aerosol-generating article defined by the rod preferably has a diameter of approximately 3.7 to 9 millimeters, or approximately 5.7 to 7.9 millimeters. The aerosol-generating article may have a total length of approximately 30 millimeters to approximately 100 millimeters. In one preferred embodiment, the aerosol-generating article has a total length of approximately 45 millimeters.

[0041] The air-permeable portion of the outer wall of the rod preferably comprises at least one annular air-permeable zone. The use of the annular air-permeable zone provides for uniform radial inflow of cooling air into the interior of the aerosol-generating article around the periphery of the article and improved mixing with the hot aerosol emitted from the aerosol-forming substrate.

[0042] Advantageously, the at least one breathable zone in the outer wall of the rod may include a first annular breathable zone and a second annular breathable zone. The first and second zones may be axially spaced apart from one another along the longitudinal axis of the rod and have distinct first and second permeabilities to airflow therethrough. Providing the first and second annular breathable zones with different permeabilities to airflow may enable correspondingly different flow rates through the first and second annular zones. This may in turn enable different levels of cooling to be achieved in different regions within the aerosol-generating article.

[0043] Preferably, the breathable portion of the rod's outer wall may have an axial length of 0.2 to 4 millimeters, or more preferably 0.2 to 2.5 millimeters, or more preferably 0.2 to 1.8 millimeters, or more preferably 0.2 to 1.5 millimeters. Limiting the axial length of the breathable portion of the rod's outer wall may help concentrate mixing of the cooling air received through the breathable portion with the aerosol emitted from the substrate into a narrow mixing region located downstream of the substrate.

[0044] Advantageously, the breathable portion of the outer wall of the rod may extend downstream of the aerosol-forming substrate by no more than 4 millimeters, or preferably no more than 2.5 millimeters, or more preferably no more than 1.8 millimeters, or more preferably no more than 1.5 millimeters, or more preferably no more than 0.2 millimeters. By limiting the breathable portion to extend downstream from the aerosol-forming substrate to no more than a certain distance, mixing of the cooled air received through the breathable portion with the aerosol emitted from the substrate can be achieved immediately downstream of the substrate. This helps ensure that the user receives a thoroughly mixed inhalable vapor when the mixed flow reaches the mouth end of the rod, thereby enhancing the user experience.

[0045] Advantageously, the article and device may be configured such that, when the article is docked in the device and suction is applied to the mouth end, 50% to 90% of the combined volumetric flow along the first and second airflow paths flows through the breathable portion of the rod's exterior wall along the second airflow path. Advantageously, the article and device may be configured such that, when the article is docked in the device and suction is applied to the mouth end, 55% to 75% of the combined volumetric flow along the first and second airflow paths flows through the breathable portion of the rod's exterior wall along the second airflow path. The proportion of the combined volumetric flow that flows along the second airflow path rather than the first airflow path is affected by the degree of breathability of the breathable portion of the rod's exterior wall and the nature of the aerosol-forming substrate within the rod. For example, different aerosol-forming substrates present different resistances to drawing on the first airflow path, and the resistance to drawing is also affected by factors such as compaction of the substrate (e.g., when the substrate is a solid aerosol-forming substrate).

[0046] According to a third aspect of the present disclosure, there is provided an aerosol-generating article for use in an aerosol-generating device. The aerosol-generating article defines a rod. The rod contains an aerosol-forming substrate and has a distal end and a mouth end, the mouth end being located downstream of the distal end. The aerosol-generating article comprises a first airflow path and a second airflow path. The outer wall of the rod comprises an air-permeable portion, the air-permeable portion of the outer wall of the rod being located downstream of the aerosol-forming substrate. The first airflow path extends downstream along the interior of the rod through the aerosol-forming substrate toward the mouth end, such that upon application of suction to the mouth end, air is drawn into the aerosol-generating article and passes through the aerosol-forming substrate along the interior of the rod downstream toward the mouth end. The second airflow path extends through the air-permeable portion of the outer wall of the rod to supply cooling air from outside the rod to a mixing region within the rod. The breathable portion and the mixing region are located together downstream of and immediately adjacent to the aerosol-forming substrate so that, in use, the airflow along the second airflow path mixes with the aerosol flow along the first airflow path in the mixing region.

[0047] It will be appreciated that the aerosol-generating article of this third aspect is suitable for use with the aerosol-generating device of the first aspect discussed in the preceding paragraph and may also correspond to an aerosol-generating article forming part of the aerosol delivery system of the second aspect of the present disclosure.

[0048] By locating the breathable portion and the mixing region downstream of and immediately adjacent to the aerosol-forming substrate, the air received through the breathable portion of the outer wall of the rod and flowing along the second airflow path may efficiently cool the hot aerosol emitted from the heating of the aerosol-forming substrate and flowing along the first airflow path. Locating the breathable portion and the mixing region downstream of and immediately adjacent to the aerosol-forming substrate may also ensure that the cooled air and the aerosol are thoroughly mixed before reaching the mouth end of the rod. Efficient mixing of the cooled air and the aerosol within the rod of the aerosol-generating article is important in providing an enhanced experience to users of the system. This efficient mixing of the cooled air and the aerosol is in contrast to conventional ventilated cigarettes, which introduce air into the cigarette through perforations provided far downstream from the aerosol-forming substrate at or very close to the mouth end of the cigarette. Conventional ventilated cigarettes do not achieve efficient mixing of the incoming ventilation air with the hot aerosol gas, which can lead to a poor user experience.

[0049] Preferably, the aerosol-forming substrate is located at the distal end of the rod or closer to the rod distal end than to the rod oral end.

[0050] The interior of the rod is preferably free of obstructions from the mixing region to the mouth end, so that the combined flow is unimpeded when flowing from the mixing region to the mouth end during use. For example, the aerosol-generating article may lack a mouthpiece filter or aerosol cooling element that would impede the downstream flow path toward the mouth end, as commonly found in known e-cigarettes. The lack of any such obstructions within the interior of the rod may help reduce the draw resistance of the first and second airflow paths and may also help reduce the amount of suction a user needs to apply at the mouth end to inhale a given volume of the combined flow of aerosol and cooled air. This may also reduce the complexity of manufacturing the article.

[0051] As described with respect to the aerosol delivery system of the second aspect of the present disclosure, the breathable portion of the rod's exterior wall may comprise one or more of a porous material, a plurality of slits, or a plurality of holes. By way of example and without limitation, the breathable portion of the rod's exterior wall may be provided as a mesh, with interstices defining openings within the mesh, thereby providing permeability for airflow through the mesh (i.e., through the exterior wall of the rod). In a further alternative, the breathable portion of the rod's exterior wall may comprise a plurality of voids, in which the voids define voids within the material of the exterior wall. The size of any voids, slits, or holes that may form part of the breathable portion of the rod's exterior wall directly affects the permeability of the breathable portion to airflow. The size of any such voids, slits, or holes may be selected according to the desired volumetric flow rate of cooling air within the interior of the aerosol-generating article.

[0052] When the aerosol-generating article is a smoking article used to generate an aerosol that is inhalable directly into the user's lungs through the user's mouth, the outer wall of the rod may be provided as cigarette paper, with perforations provided in the cigarette paper to form breathable portions of the outer wall of the rod.

[0053] Again, as described with respect to the aerosol delivery system of the second aspect of the present disclosure, the air-permeable portion of the outer wall of the rod may preferably comprise at least one annular air-permeable zone. The use of the annular air-permeable zone provides for uniform radial inflow of cooling air into the interior of the aerosol-generating article around the periphery of the article and improved mixing with the hot aerosol stream emanating from the aerosol-forming substrate.

[0054] Advantageously, the at least one annular breathable zone includes a first annular breathable zone and a second annular breathable zone. The first and second zones may be axially spaced apart from one another along the longitudinal axis of the rod and have distinct first and second permeabilities to airflow therethrough. Providing the first and second annular breathable zones with different permeabilities to airflow may enable correspondingly different flow rates through the first and second annular zones. Accordingly, this may enable different levels of cooling to be achieved in different regions within the aerosol-generating article, depending on whether those regions are adjacent to the first or second annular zones having their respective different permeabilities to airflow.

[0055] As described with respect to the aerosol delivery system of the second aspect of the present disclosure, the breathable portion of the outer wall of the rod may preferably have an axial length of 0.2 to 4 millimeters, or more preferably 0.2 to 2.5 millimeters, or more preferably 0.2 to 1.8 millimeters, or more preferably 0.2 to 1.5 millimeters. Limiting the axial length of the breathable portion of the outer wall of the rod may help to concentrate the mixing of the cooling air received through the breathable portion with the aerosol emitted from the substrate in a narrow region located downstream of the substrate.

[0056] As described with respect to the aerosol delivery system of the second embodiment, the breathable portion of the outer wall of the rod may advantageously extend downstream of the aerosol-forming substrate by no more than 4 millimeters, or preferably no more than 2.5 millimeters, or more preferably no more than 1.8 millimeters, or more preferably no more than 1.5 millimeters, or more preferably no more than 0.2 millimeters. By limiting the breathable portion to extend downstream from the aerosol-forming substrate to no more than a certain minimum distance, mixing of the cooled air received through the breathable portion with the aerosol emitted from the substrate can be achieved immediately downstream of the substrate. This helps ensure that the user receives a thoroughly mixed inhalable vapor when the mixed flow reaches the mouth end of the rod.

[0057] As described with respect to the aerosol delivery system of the second aspect of the present disclosure, the article is advantageously configured such that, upon application of suction to the mouth end, 50% to 90% of the combined volumetric flow along the first and second airflow paths flows through the breathable portion of the rod's exterior wall along the second airflow path. Conveniently, the article may be configured such that, upon application of suction to the mouth end of the aerosol-generating article, 55% to 75% of the combined volumetric flow along the first and second airflow paths flows through the breathable portion of the rod's exterior wall along the second airflow path. The proportion of the combined volumetric flow that flows along the second airflow path rather than the first airflow path is influenced by the degree of breathability of the breathable portion of the rod's exterior wall and the nature of the aerosol-forming substrate within the rod. For example, different aerosol-forming substrates present different resistances to drawing on the first airflow path, and the resistance to drawing is also influenced by factors such as compaction of the substrate (e.g., when the substrate is a solid aerosol-forming substrate).

[0058] The present invention is defined in the claims. However, the following provides a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of any other example, embodiment, or aspect described herein.

[0059] Example 1: An aerosol generating device configured for use in heating an aerosol-generating article to generate an inhalable aerosol from an aerosol-forming substrate of the aerosol-generating article, the aerosol generating device comprising a housing, the housing comprising a cavity configured to receive the aerosol-generating article, the housing adapted to define a cooling airflow path extending from an exterior of the housing, through an interior of the housing, to an air-permeable portion of a wall of the cavity. Example 2: An aerosol generating device as described in Example 1, in which, when used with an aerosol-generating article docked within the cavity, the breathable portion of the cavity wall coincides with a corresponding breathable portion of the outer wall of the aerosol-generating article. Example 3: An aerosol generating device as described in either Example 1 or Example 2, wherein the wall of the cavity is tubular, the cavity is provided with an open end and a closed end, and the aerosol generating device is configured to receive an aerosol-generating article through the open end of the tubular cavity. Example 4: An aerosol generating device according to any one of Examples 1 to 3, wherein the breathable portion of the cavity wall comprises one or more of a porous material, a plurality of slits, and a plurality of holes. Example 5: An aerosol generating device according to any one of Examples 1 to 4, wherein the wall of the cavity is tubular and the breathable portion of the wall of the cavity comprises at least one annular breathable zone. Example 6: An aerosol generating device as described in Example 5, wherein the at least one annular breathable zone comprises a first annular breathable zone and a second annular breathable zone, the first zone and the second zone being axially spaced apart from each other along the longitudinal axis of the cavity and having distinct first and second permeabilities to airflow through the annular breathable zones. Example 7: An aerosol generating device as described in any one of Examples 1 to 6, wherein the aerosol generating device further comprises control electronics provided within the housing, and wherein the cooling airflow path extends through or adjacent to the control electronics to provide cooling to the control electronics. Example 8: An aerosol generating device according to any one of Examples 1 to 7, wherein the aerosol generating device is configured to force a flow of air from outside the housing along a cooling airflow path towards a breathable portion of the wall of the cavity. Example 9: An aerosol-generating apparatus according to any one of Examples 1 to 8, wherein the aerosol-generating apparatus is an electrical apparatus for heating the aerosol-forming substrate of the aerosol-generating article by either or both of induction heating and resistance heating, the apparatus comprising a power source for supplying electrical power. Example 10: An aerosol generating device as described in Example 9, wherein the wall of the cavity comprises a susceptor portion, the susceptor portion being axially spaced apart from the air-permeable portion of the wall of the cavity along the longitudinal axis of the cavity, and the aerosol generating device further comprises an inductor coil surrounding the susceptor portion. Example 11: An aerosol generating device as described in either Example 9 or Example 10, wherein the device comprises a resistive heating element provided within the cavity and configured, in use, to surround or be inserted into an aerosol-generating article docked within the cavity. Example 12: An aerosol delivery system comprising: an aerosol-generating device according to any one of Examples 1 to 11; and an aerosol-generating article, the aerosol-generating article defining a rod, the rod containing an aerosol-forming substrate, the outer wall of the rod comprising a breathable portion, the breathable portion of the outer wall of the rod being positioned downstream of the aerosol-forming substrate, wherein the device and article are configured such that when the aerosol-generating article is docked within the cavity, the breathable portion of the wall of the cavity coincides with the breathable portion of the outer wall of the rod. Example 13: An aerosol delivery system as described in Example 12, wherein the aerosol-generating article further comprises a first airflow path and a second airflow path, the rod having an oral end and a distal end, the oral end being located downstream of the distal end, the first airflow path extending downstream toward the oral end along the interior of the rod through the aerosol-forming substrate, whereby, upon application of suction at the oral end, air is drawn into the aerosol-generating article and downstream toward the oral end along the interior of the rod through the aerosol-forming substrate, and the second airflow path extends through an air-permeable portion of the outer wall of the rod when the article is docked within the cavity of the device, to supply cooled airflow received from the cooled airflow path to a mixing region within the rod, to the air-permeable portion, and to a mixing region located downstream of and immediately adjacent to the aerosol-forming substrate, whereby, in use, the airflow along the second airflow path mixes with the aerosol flow along the first airflow path in the mixing region. Example 14: An aerosol delivery system as described in Example 13, wherein the aerosol-forming substrate is located at the distal end or closer to the distal end than to the oral end. Example 15: An aerosol delivery system described in either Example 13 or Example 14, wherein the interior of the rod is free of obstructions from the mixing region to the mouth end, such that in use, the mixed flow is not impeded as it flows from the mixing region to the mouth end. Example 16: An aerosol delivery system described in any one of Examples 12 to 15, wherein the breathable portion of the outer wall of the rod comprises one or more of a porous material, a plurality of slits, and a plurality of holes. Example 17: An aerosol delivery system described in any one of Examples 12 to 16, wherein the breathable portion of the outer wall of the rod comprises at least one annular breathable zone. Example 18: An aerosol delivery system as described in Example 17, wherein at least one breathable zone on the outer wall of the rod comprises a first annular breathable zone and a second annular breathable zone, the first zone and the second zone being axially spaced apart from each other along the longitudinal axis of the rod and having distinct first and second permeabilities to airflow through the annular breathable zones. Example 19: An aerosol delivery system described in any one of Examples 12 to 18, wherein the breathable portion of the outer wall of the rod has an axial length of 0.2 to 4 millimeters, or 0.2 to 2.5 millimeters, or 0.2 to 1.8 millimeters, or 0.2 to 1.5 millimeters. Example 20: An aerosol delivery system described in any one of Examples 12 to 19, wherein the breathable portion of the outer wall of the rod extends downstream of the aerosol-forming substrate by no more than 4 millimeters, or no more than 2.5 millimeters, or no more than 1.8 millimeters, or no more than 1.5 millimeters, or no more than 0.2 millimeters. Example 21: An aerosol delivery system described in any of Examples 13-20, wherein the aerosol-generating article and aerosol-generating device are configured such that upon application of suction to the oral end with the article docked in the device, 50% to 90% of the combined volumetric flow along the first airflow path and the second airflow path flows through the breathable portion of the outer wall of the rod along the second airflow path. Example 22: An aerosol delivery system as described in Example 21, wherein the aerosol-generating article and aerosol-generating device are configured such that upon application of suction to the mouth end with the article docked in the device, 55% to 75% of the combined volumetric flow along the first airflow path and the second airflow path flows through the breathable portion of the outer wall of the rod along the second airflow path. Example 23: An aerosol-generating article for use in an aerosol-generating device, the aerosol-generating article defining a rod, the rod containing an aerosol-forming substrate and having an oral end and a distal end, the oral end being located downstream of the distal end, the aerosol-generating article comprising a first airflow path and a second airflow path, an outer wall of the rod comprising a breathable portion, the breathable portion of the outer wall of the rod being located downstream from the aerosol-forming substrate, the first airflow path extending downstream towards the oral end along an interior of the rod and through the aerosol-forming substrate, whereby an aerosol-generating article wherein, upon application of suction to the mouth end, air is drawn into the aerosol-generating article and downstream toward the mouth end along the interior of the rod and past the aerosol-forming substrate, and a second airflow path extends through an air-permeable portion of the outer wall of the rod to supply a cooled airflow from outside the rod to a mixing region within the rod, the air-permeable portion, and a mixing region located downstream of and immediately adjacent to the aerosol-forming substrate, whereby, in use, the airflow along the second airflow path mixes with the aerosol flow along the first airflow path in the mixing region. Example 24: An aerosol-generating article as described in Example 23, wherein the aerosol-forming substrate is located at the distal end of the rod or closer to the distal end of the rod than to the oral end of the rod. Example 25: An aerosol delivery system described in either Example 23 or Example 24, wherein the interior of the rod is free of obstructions from the mixing region to the mouth end, such that, in use, the mixed flow is not impeded as it flows from the mixing region to the mouth end. Example 26: An aerosol-generating article according to any one of Examples 22 to 25, wherein the breathable portion comprises one or more of a porous material, a plurality of slits, and a plurality of holes. Example 27: An aerosol-generating article according to any one of Examples 23 to 26, wherein the breathable portion of the outer wall of the rod comprises at least one annular breathable zone. Example 28: An aerosol-generating article as described in Example 27, wherein at least one annular breathable zone comprises a first annular breathable zone and a second annular breathable zone, the first zone and the second zone being axially spaced apart from each other along the longitudinal axis of the rod and having distinct first and second permeabilities to airflow through the annular breathable zones. Example 29: An aerosol-generating article described in any one of Examples 23 to 28, in which the breathable portion of the outer wall of the rod has an axial length of 0.2 to 4 mm, or 0.2 to 2.5 mm, or 0.2 to 1.8 mm, or 0.2 to 1.5 mm. Example 30: An aerosol-generating article described in any one of Examples 23 to 29, wherein the breathable portion of the outer wall of the rod extends downstream of the aerosol-forming substrate by no more than 4 millimeters, or no more than 2.5 millimeters, or no more than 1.8 millimeters, or no more than 1.5 millimeters, or no more than 0.2 millimeters. Example 31: An aerosol-generating article described in any of Examples 23 to 30, wherein the article is configured such that upon application of suction to the mouth end, 50% to 90% of the combined volumetric flow along the first airflow path and the second airflow path flows through the breathable portion of the outer wall of the rod along the second airflow path. Example 32: An aerosol-generating article as described in Example 31, wherein the article is configured such that upon application of suction to the mouth end, 55% to 75% of the combined volumetric flow along the first airflow path and the second airflow path flows through the breathable portion of the outer wall of the rod along the second airflow path.

[0060] The embodiments will now be further described with reference to the following figures: [Brief explanation of the drawings]

[0061] [Figure 1] FIG. 1 illustrates a perspective view of an aerosol generating device according to the present disclosure. [Figure 2] FIG. 2 illustrates a further perspective view of the aerosol generating device of FIG. 1, with a portion of the device's housing removed to allow viewing of the interior of the device. [Figure 3] FIG. 3 corresponds to the view of FIG. 2, but with the aerosol-generating article coupled to an aerosol-generating device to provide an aerosol delivery system. [Figure 4] FIG. 4 illustrates a perspective view of the aerosol-generating article shown in FIG. [Figures 5a-5c] 5a, 5b, and 5c illustrate three different side elevational views of the aerosol-generating article of FIG. [Figure 6a-6b] Figures 6a and 6b relate to a second embodiment and show a detailed view of a) a portion of the cavity wall of the device and b) a portion of the outer wall of the article. DETAILED DESCRIPTION OF THE INVENTION

[0062] 1 shows an aerosol generating device 100. The device 100 has a housing 101. An activation button 102 is integrated into the housing 101.

[0063] 2, a power source in the form of a rechargeable battery 103 is located within housing 101. Control electronics 104 is also located within housing 101. Control electronics 104 is positioned adjacent to rechargeable battery 103. Housing 101 has a tubular cavity 105 extending within the interior of device 100. Cavity 105 is defined by a tubular wall 106 that extends into device 100 along a longitudinal axis 107. Cavity 105 has an open end 108 and a closed end 109, with the open end and closed end being located at opposite ends of the cavity. Housing 101 is provided with a slidable cover 110 that can be moved to expose or close open end 108 of cavity 105.

[0064] As shown in FIGS. 2 and 3 , the tubular wall 106 has a lower portion 106a and an upper portion 106b. The lower portion 106a is formed of a different material than the upper portion 106b. The lower portion 106a is formed of a material capable of absorbing electromagnetic energy and converting it to heat. Therefore, in this embodiment, the lower portion 106a is the susceptor portion. Accordingly, the terms lower portion and susceptor portion are used interchangeably with reference to 106a. In this example, the susceptor portion 106a is formed of steel. However, in other embodiments (not shown), the susceptor portion 106a may be formed of other materials capable of absorbing electromagnetic energy and converting it to heat. An inductor coil 111 circumferentially surrounds the susceptor portion 106a. The upper portion 106b of the tubular wall 106 is formed of a polymeric material. An annular region of the upper portion 106 b of the tubular wall 106 of the cavity 105 is provided with a uniform distribution of holes extending radially through the tubular wall to form an annular breathable zone 112 .

[0065] 2 and 3, a row of air inlets 113 is provided on the bottom surface of housing 101, and a circular arrangement of air inlets 114 is provided on the sidewall of housing 101. As shown by the fluid flow lines in FIG. 3, air entering housing 101 through air inlets 113, 114 flows through the interior of the housing and is in fluid communication with annular breathable band 112.

[0066] 3, a single air inlet 115 is also provided in the bottom surface of the housing 101 directly below the closed end 109 of the cavity 105, with a fluid flow channel extending from the air inlet 115 to an opening (not shown) formed in the closed end 109 of the cavity 105. Fluid flow lines are included in FIG. 3 showing how air entering through the air inlet 115 is in fluid communication with the closed end 109 of the cavity 105.

[0067] 3, the aerosol-generating article 100 is used in conjunction with an aerosol-generating device 200. The aerosol-generating device 100 and the aerosol-generating article 200 together form an aerosol delivery system 300.

[0068] 4, the aerosol-generating article 200 has the form of an elongated cylindrical rod. Accordingly, the terms aerosol-generating article and rod are used interchangeably herein with reference to the reference numeral 200. The aerosol-generating article 200 has a diameter d of approximately 3.7 to 9 millimeters. 200 However, in an alternative embodiment, the diameter d 200 is approximately 5.7 to 7.9 millimeters. The aerosol-generating article 200 has a distal end 201 and a mouth end 202. The aerosol-generating article 200 has a cigarette paper wrapper 203. The wrapper 203 forms the outer wall of the rod 200. As shown in Figures 5b and 5c, a porous forward plug 204, a plug of aerosol-forming substrate 205, and a tubular core element 206 are assembled sequentially and coaxially within the wrapper 203. The porous forward plug 204 is located at the distal end 201. The plug of aerosol-forming substrate 205 is positioned immediately downstream of the forward plug 204. The tubular core element 206 is positioned immediately downstream of the plug of aerosol-forming substrate 205 and extends downstream toward the mouth end 202. In the embodiment shown, the hollow interior 207 of the tubular core element 206 is free of obstructions, such as a mouthpiece filter element, to define an empty space. Thus, the hollow interior 207 means that the interior of the rod 200 between the downstream end of the aerosol-forming substrate 205 and the mouth end 202 defines an unobstructed flow path. However, in an alternative embodiment (not shown), a filter element may be located within the rod 200 adjacent the mouth end 202. For the embodiment shown and described herein, the aerosol-forming substrate 205 is a tobacco-containing solid substrate. The annular region of the wrapper 203 is provided with a uniform distribution of holes extending radially through the tubular wall, forming an annular breathable zone 208 within the wrapper 203 (i.e., outer wall) of the rod 200.

[0069] A first airflow path 209 extends through the aerosol-forming substrate 205 and along the hollow interior 207 of the tubular core element 206. A second airflow path 210 extends through the annular breathable zone 208 to a mixing region 211 located within the rod 200. The mixing region 211 is where the first airflow path 209 and the second airflow path 210 coincide and their respective fluid flows intermix and combine, as described in more detail below.

[0070] The aerosol-generating article 200 shown in the figures and described herein is a smoking article intended for use in an aerosol-generating device 100 to generate an aerosol from an aerosol-forming substrate 205 for inhalation by a user. While the aerosol-generating device 100 is reusable, the aerosol-generating article 200 is disposable and intended for single use only.

[0071] During use, a user would first slide the slidable cover 110 to expose the open end 108 of the cavity 105. The user would then insert a new, unused aerosol-generating article 200 into the cavity 105 via the open end 108 until the distal end 201 of the article touches the closed end 109 of the cavity. In this position, the aerosol-generating article 200 is said to be docked within the cavity 105 of the aerosol-generating device 200. The combination of the aerosol-generating device 100 and the aerosol-generating article 200 forms an aerosol delivery system 300. When the aerosol-generating article 200 is docked within the cavity 105, the annular breathable zone 112 of the tubular wall 106 of the cavity 105 mates with the annular breathable zone 208 of the wrapper 203 of the aerosol-generating article 200. Furthermore, when the aerosol-generating device 200 is docked in the cavity 105, the plug of the aerosol-forming substrate 205 is located entirely within the susceptor portion 106a and the inductor coil 111.

[0072] As the user presses the activation button 102, the control electronics 104 controls the supply of power from the rechargeable battery 103 to the inductor coil 111. The resulting current flow through the inductor coil 111 induces eddy currents in the steel susceptor portion 106a. These eddy currents then result in heating of the susceptor portion 106a. Heat from the susceptor portion 106a is radiated onto the aerosol-generating article 200 contained within the cavity 105. Because the plug of the aerosol-forming substrate 205 is completely located within the susceptor portion 106a and the inductor coil 111, heat from the susceptor portion is radiated onto the wrapper 203 of the aerosol-generating article 200 and conducted to the plug of the aerosol-forming substrate 205. The resulting heating of the aerosol-forming substrate 205 causes the substrate to emit an aerosol.

[0073] The control electronics 104 are configured to regulate the temperature of the susceptor portion 106a according to a predetermined thermal profile. Once the susceptor portion 106a reaches a temperature high enough to generate an aerosol from the plug of aerosol-forming substrate 205, the user may then draw on the mouth end 202 of the aerosol-generating article 200 to apply suction to the mouth end. Each draw by the user on the aerosol-generating article 200 is generally referred to as a "puff."

[0074] Suction created by a user sucking on the mouth end 202 causes air to be drawn into the aerosol-generating device 100 via the inlet opening 115 and carried through the closed end 109 of the cavity 105. The suction causes this air to flow along the first airflow path 209 by entering the aerosol-generating article 200 through the porous front plug 204 and forward through the plug of the aerosol-forming substrate 205. Due to heating by the susceptor portion 106a, this air becomes entrained with aerosol emitted by the aerosol-forming substrate 205 and continues along the first airflow path 209 to emerge from the downstream end of the plug of the aerosol-forming substrate 205 into the mixing region 211.

[0075] The suction created by the user sucking on the oral end 202 also causes external air to be drawn into the housing 101 of the aerosol generating device 100 via the air inlets 113, 114. This air then flows past the battery 103 and control electronics 104 within the interior of the housing 101, thereby serving to cool both the battery 103 and the control electronics 104. This air then flows forward to and through an annular breathable zone 112 defined in the upper portion 106b of the tubular wall 106 of the cavity 105. The matching alignment of the annular breathable zone 112 defined in the tubular wall 106 of the cavity 105 of the device 100 and the annular breathable zone 208 defined in the wrapper 203 of the aerosol-generating article 200 results in the majority of the air flowing through the breathable zone 112, then passing across the radial gap separating the tubular wall 106 and the article 200 and through the breathable zone 208 along a second airflow path 210. In this manner, external air can be supplied through the interior of the housing 101 of the aerosol-generating device 100 to provide cooling to the battery 103 and control electronics 104, and then into the aerosol-generating article 200 docked within the cavity 105. Upon passing through the annular breathable zone 208 defined in the wrapper 203 of the article 200, the external air enters a mixing region 211.

[0076] In the mixing region 211, the heated aerosol flowing along the first airflow path 209 mixes with the cooled external air flowing along the second airflow path 210, resulting in cooling of the aerosol. The cooled mixed air then flows downstream along the hollow interior 207 of the tubular core element 206 towards the oral end 202 and is inhaled by the user.

[0077] In the illustrated aerosol-generating article 200, the annular breathable zone 208 has an axial length L of 4 millimeters. 208 , with the upstream end of the annular band 208 approximately coinciding with the downstream end of the plug of aerosol-forming substrate 205. In an alternative embodiment, the axial length L 208The aerosol-generating article 200 shown in the figures may have a length of from about 30 millimeters to about 100 millimeters.

[0078] In an alternative embodiment, as shown in FIG. 6a, the annular breathable zone 112 of the tubular wall 106 of the cavity 105 of the aerosol generating device 100 is formed from two annular zones: a first annular zone 112a and a second annular zone 112b. FIG. 6a illustrates region "A" (see FIG. 3) of the tubular wall 106. The first annular zone 112a and the second annular zone 112b are axially spaced apart from one another along the longitudinal axis 107, with the first annular zone 112a being closer to the closed end 109 of the cavity 105 than the second annular zone 112b. However, the first annular zone 112a and the second annular zone 112b have distinct (i.e., different) levels of permeability to airflow therethrough. In the embodiment shown in FIG. 6a, both the annular zone 112a and the annular zone 112b are provided with a uniform arrangement of holes extending through the tubular wall 106. However, the holes in the first annular zone 112a are larger in area than the holes in the second annular zone 112b. This difference in hole area has the effect that, in use, a greater volumetric flow of external cooling air flows through the first annular zone 112a than through the second annular zone 112b. This difference in volumetric flow rate provides differential cooling along the length or axis 107 of the cavity 105. To complement the first annular zone 112a and second annular zone 112b provided in the tubular wall 106 of the aerosol-generating device 100, the annular breathable zone 208 of the wrapper 203 of the aerosol-generating article 200 is similarly formed from two annular zones, namely, a first annular zone 208a and a second annular zone 208b (as shown in FIG. 6b). FIG. 6b shows region "B" (see FIG. 4) of the wrapper 203 of the aerosol-generating article 200. The first annular band 208a and the second annular band 208b are axially spaced apart from one another along the length of the article 200, with the first annular band 208a being closer to the distal end 201 of the article 200 than the second annular band 208b. However, the first annular band 208a and the second annular band 208b have distinct (i.e., different) levels of permeability to airflow therethrough. In the embodiment shown in FIG. 6b, both the annular bands 208a and 208b are provided with a uniform arrangement of holes extending through the wrapper 203. However, the holes in the first annular band 208a are larger in area than the holes in the second annular band 208b.This difference in hole area has the effect that, in use, a greater volumetric flow of air flows through the first annular zone 208a than through the second annular zone 208b. This difference in volumetric flow rates provides differential cooling within the interior of the article 200 along the length of the article, with a higher level of cooled air being introduced closer to the aerosol-forming substrate but immediately downstream, i.e., via the first annular zone 208a. The first annular zones 112a, 208a and second annular zones 112b, 208b of the apparatus 100 and article 200 are arranged such that, when the articles are docked within the cavity 105 of the apparatus, the first annular zone 112a of the apparatus coincides with the first annular zone 208a of the article, and the second annular zone 112b of the apparatus coincides with the second annular zone 208b of the article. 6a and 6b, the first annular bands 112a, 208a are of equal length and completely overlap one another, and likewise, the second annular bands 112b, 208b are of equal length and completely overlap one another. However, in a further alternative embodiment (not shown), the first annular bands 112a, 208a may instead only partially overlap, and likewise, the second annular bands 112b, 208b may instead only partially overlap.

[0079] As an alternative to using different hole sizes in the first annular zone 112a, 208a and the second annular zone 112b, 208b, different air permeabilities in the first and second zones may instead be provided by using different hole densities in the first and second zones, or by using materials with different porosities for the first and second zones.

[0080] For purposes of this specification and the appended claims, unless otherwise indicated, all numbers expressing amounts, quantities, percentages, and the like are to be understood in all instances as modified by the term "about." Also, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein, which may or may not be specifically recited herein. Accordingly, in this context, the number "A" is to be understood as "A" ± 10%. Within this context, the number "A" may be considered to include numerical values ​​that are within the common standard error for measurement of the property that the number "A" modifies. The number "A," as used in the appended claims, may, in some cases, deviate by the percentages recited above, provided that the amount by which "A" deviates does not materially affect the basic and novel property(ies) of the claimed invention. Also, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein, which may or may not be specifically recited herein.

Claims

1. 1. An aerosol generating apparatus configured for use in heating an aerosol-generating article to generate an inhalable aerosol from an aerosol-forming substrate of the aerosol-generating article, comprising: the aerosol generating device comprises a housing; the housing includes a cavity configured to receive the aerosol-generating article; the housing is adapted to define a cooling airflow path extending from an exterior of the housing, through an interior of the housing, to an air-permeable portion of a wall of the cavity; An aerosol generating device, wherein the wall of the cavity is tubular, and the air-permeable portion of the wall of the cavity has at least one annular air-permeable band, the annular air-permeable band being configured to direct airflow radially from the cooling airflow path into the cavity around the periphery of the tubular wall of the cavity.

2. 2. The aerosol generating device of claim 1, wherein an aerosol-generating article is docked within the cavity, and the air-permeable portion of the wall of the cavity coincides with a corresponding air-permeable portion of the outer wall of the aerosol-generating article.

3. 3. The aerosol generating device of claim 1, wherein the wall of the cavity is tubular, the cavity is provided with an open end and a closed end, and the aerosol generating device is configured to receive the aerosol-generating article through the open end of the tubular cavity.

4. the air permeable portion of the wall of the cavity; a porous material; A plurality of slits; The aerosol generating device according to any one of claims 1 to 3, further comprising one or more of:

5. 5. An aerosol generating device as described in any one of claims 1 to 4, wherein the at least one annular breathable zone comprises a first annular breathable zone and a second annular breathable zone, the first zone and the second zone being axially spaced apart from each other along the longitudinal axis of the cavity and having distinct first and second permeabilities to airflow through the annular breathable zones.

6. 6. An aerosol generating device as claimed in any one of claims 1 to 5, wherein the aerosol generating device is configured to force a flow of air from outside the housing along the cooling airflow path towards the breathable portion of the wall of the cavity.

7. 1. An aerosol delivery system comprising: The aerosol generating device according to any one of claims 1 to 6, an aerosol-generating article defining a rod, the rod containing an aerosol-forming substrate, an outer wall of the rod having an air-permeable portion, the air-permeable portion of the outer wall of the rod being positioned downstream of the aerosol-forming substrate; an aerosol delivery system comprising: a device and an article configured such that when the aerosol-generating article is docked in the cavity, the breathable portion of the wall of the cavity coincides with the breathable portion of the outer wall of the rod.

8. the aerosol-generating article further comprises a first airflow path and a second airflow path; the rod having an oral end and a distal end, the oral end being downstream from the distal end; the first airflow path extends downstream toward the mouth end along the interior of the rod and through the aerosol-forming substrate, whereby upon application of suction at the mouth end, air is drawn into the aerosol-generating article and downstream toward the mouth end along the interior of the rod and through the aerosol-forming substrate; 8. The aerosol delivery system of claim 7, wherein the second airflow path extends through the breathable portion of the outer wall of the rod when the article is docked in the cavity of the device, and supplies cooled airflow received from the cooled airflow path to a mixing region within the rod, the breathable portion, and the mixing region located downstream of and immediately adjacent to the aerosol-forming substrate, whereby, in use, the airflow along the second airflow path mixes with the aerosol flow along the first airflow path in the mixing region to provide a mixed flow.

9. The air permeable portion of the outer wall of the rod is a porous material; A plurality of slits; 9. The aerosol delivery system of claim 7 or 8, comprising one or more of: a plurality of holes;

10. 1. An aerosol-generating article for use in an aerosol-generating device, the aerosol-generating article defining a rod, the rod containing an aerosol-forming substrate and having a distal end and an oral end, the oral end being located downstream from the distal end; the aerosol-generating article comprises a first airflow path and a second airflow path; an outer wall of the rod having an air permeable portion, the air permeable portion of the outer wall of the rod being positioned downstream of the aerosol-forming substrate; the first airflow path extends downstream toward the mouth end along the interior of the rod and through the aerosol-forming substrate, whereby upon application of suction to the mouth end, air is drawn into the aerosol-generating article and downstream toward the mouth end along the interior of the rod and through the aerosol-forming substrate; the second airflow path extends through the air-permeable portion of the outer wall of the rod to supply cooled air from outside the rod to a mixing region within the rod, to the air-permeable portion, and to the mixing region located downstream of and immediately adjacent to the aerosol-forming substrate, so that, in use, airflow along the second airflow path mixes with the aerosol flow along the first airflow path in the mixing region; The air-permeable portion of the outer wall of the rod comprises at least one annular air-permeable zone, the at least one annular air-permeable zone comprising a first annular air-permeable zone and a second annular air-permeable zone, the first and second zones being axially spaced apart from one another along the longitudinal axis of the rod and having distinct first and second permeabilities to airflow through the annular air-permeable zones.

11. 11. The aerosol-generating article of claim 10, wherein the aerosol-forming substrate is located at the distal end of the rod or closer to the distal end of the rod than to the oral end of the rod.

12. 12. The aerosol-generating article of claim 10 or 11, wherein the interior of the rod is free of obstructions from the mixing region to the mouth end, so that in use the mixed flow is unimpeded as it flows from the mixing region to the mouth end.

13. The breathable portion is a porous material; A plurality of slits; and a plurality of holes.

14. 14. An aerosol-generating article according to any one of claims 10 to 13, wherein the breathable portion of the outer wall of the rod has an axial length of from 0.2 to 4 mm, or from 0.2 to 2.5 mm, or from 0.2 to 1.8 mm, or from 0.2 to 1.5 mm.

15. 15. The aerosol-generating article of any one of claims 10 to 14, wherein the breathable portion of the outer wall of the rod extends downstream of the aerosol-forming substrate by no more than 4 millimeters, or by no more than 2.5 millimeters, or by no more than 1.8 millimeters, or by no more than 1.5 millimeters, or by no more than 0.2 millimeters.

Images