Aerosol generating system

Abstract

An aerosol-generating system (2) comprising:-a housing (4) defining an oven cavity (6) having a bottom surface (10) and an open portion (12); -a tobacco rod (20) received in the oven cavity (6), the tobacco rod having a first end (22) facing the bottom surface (10); and-a first airflow path (44) extending through the oven cavity (6) and the tobacco rod (20), the first airflow path having an inlet (50) and an outlet (52), the inlet (50) comprising a nozzle (41) mounted on the bottom surface (10) of the oven cavity (6) and extending through the first end (22). The tobacco rod (20) includes an acetate fiber tube (24) adjacent to the first end (22), the acetate fiber tube (24) including an interior passage (32) through which a first airflow path (44) extends.

Description

Technical Field

[0001] The present invention relates to an aerosol generating system comprising a housing and a tobacco rod. More particularly, the present invention relates to such an aerosol generating system in the form of an electronic cigarette, an electronic cigarette, a steam inhaler, an inhalation device and related devices. Background Art

[0002] Figure 1 and Figure 2 A conventional aerosol generating system 202 is shown.

[0003] The conventional aerosol generating system 202 includes a housing 204 having an oven cavity 206 . Figure 1 is a cross-sectional view of the wall housing 204 . Figure 2 is a detailed cross-sectional view of the oven cavity 206. Figure 2 As shown, oven cavity 206 includes cylindrical wall 208 , bottom surface 210 , and open portion 212 .

[0004] The aerosol generating system 202 further comprises a tobacco rod 214. The tobacco rod 214 comprises a first end 216 facing the bottom surface 210 and a second end 218 longitudinally opposite the first end 216.

[0005] With this arrangement, Figure 2 The airflow path schematically depicted by arrows 220 in FIG. 2 extends through the oven cavity 206 and the tobacco rod 214. Figure 2 As can be seen in FIG. 2 , the airflow path 220 first extends through the opening portion 212, through the radial gap between the tobacco rod 214 and the cylindrical surface 208, through the first end 116 of the tobacco rod 214, through the tobacco particles contained in the tobacco rod 214, and through the second end 218 of the tobacco rod 214. The cylindrical surface 208 is capable of heating the tobacco product contained in the tobacco rod 214. By doing so, the air flowing along the airflow path 220 flows through the heated tobacco particles, thereby generating an aerosol that can be inhaled by the user.

[0006] However, this airflow path design causes the oven cavity temperature to drop with each puff, as the cool air flows against the cylindrical wall 208 before entering the tobacco rod 214. This cooling of the oven wall causes the vapour to condense on the wall, causing dirt to deposit. This can be inconvenient for the user and may even result in the aerosol generating system being so dirty that the user can no longer fit the tobacco rod into the oven cavity.

[0007] WO 2022 / 049247 discloses an airflow path comprising a frustoconical outer surface mounted in an oven cavity and extending through the end of a rod-type aerosol-generating article. However, this arrangement is not entirely satisfactory because a thermal connection between the cold airflow inside the housing and the oven wall still exists and tobacco particles can fall into the oven cavity. Furthermore, this arrangement is incompatible with an arrangement in which the airflow is drawn from a position close to the second end of the tobacco rod.

[0008] There is therefore a need to facilitate maintenance of aerosol generating systems, making the oven cavity cleaner and improving organoleptic performance.It is therefore an object of the present invention to provide an improved aerosol generating system which can remedy the drawbacks of conventional solutions. Summary of the invention

[0009] The mentioned disadvantages are remedied by the subject matter of the independent claims. Further preferred embodiments of the invention are defined in the dependent claims.

[0010] According to one embodiment of the present invention, an aerosol generating system is provided, which includes: a shell defining an oven cavity, the oven cavity having a bottom surface and an opening portion; a tobacco rod at least partially received in the oven cavity, the tobacco rod having a first end facing the bottom surface; and a first airflow path extending through the oven cavity and the tobacco rod, the first airflow path having an inlet fluidly connecting the first airflow path to the outside of the oven cavity and an outlet fluidly connecting the first airflow path to the outside of the tobacco rod, the inlet including a nozzle mounted on the bottom surface of the oven cavity and extending through the first end, the tobacco rod including an acetate tube adjacent to the first end, the acetate tube including an internal channel, and the first airflow path extending through the internal channel.

[0011] By means of this embodiment, cooling of the cylindrical surface of the oven cavity is avoided. As a result, the steam no longer condenses on the cylindrical surface and dirt is discharged with the steam. Furthermore, due to the addition of the acetate tube, this embodiment avoids tobacco particles from falling into the oven cavity. This allows improved maintenance of the aerosol generating system, in particular the oven cavity is cleaner than in conventional solutions.

[0012] Preferably, the cellulose acetate tube includes a first front surface, a second front surface, a cylindrical surface extending between the first front surface and the second front surface, and an aperture extending between the cylindrical surface and the interior passage.

[0013] By means of such an orifice, a portion of the first airflow path can flow over the cylindrical surface of the acetate tube, which will not accumulate dirt. This will therefore improve the consistency of the pressure drop in the aerosol generating system and improve the user experience.

[0014] In another embodiment, the first front surface is proximate to the bottom surface and the second front surface is distal to the bottom surface, and the internal passage comprises a blind hole extending from the first front surface.

[0015] Such an embodiment prevents more tobacco products from falling into other parts of the aerosol generating system, particularly the nozzle. By doing so, the consistency of the pressure drop in the aerosol generating system is further improved.

[0016] Preferably, the nozzle includes a generally frustoconical outer surface, a first axial portion extending through the bottom surface, and a second axial portion extending through the first end to penetrate the tobacco rod, the first axial portion being close to the longer diameter end of the generally frustoconical outer surface and the second axial portion being close to the shorter diameter end of the generally frustoconical outer surface.

[0017] Preferably, the generally frustoconical outer surface comprises a plurality of circumferential ribs.

[0018] Preferably, the generally frustoconical outer surface comprises external threads.

[0019] In another embodiment, the nozzle comprises a cylindrical inner through-hole having a circular axial cross-section.

[0020] Preferably, the cylindrical inner through hole comprises an internal thread.

[0021] This design of the nozzle allows for optimal fitting and sealing of the nozzle into the tobacco rod to avoid undesirable secondary airflow while facilitating insertion of the tobacco rod.

[0022] Preferably, the tobacco rod comprises a second end portion longitudinally opposite the first end portion and a thicker portion between the first end portion and the second end portion.

[0023] This thicker portion improves the sealing of the radial gap between the tobacco rod and the cylindrical surface of the oven cavity, so that even if a depression is formed at the bottom of the oven cavity due to suction, undesirable secondary airflow from the opening portion can be avoided. Therefore, condensation of steam on the cylindrical surface of the oven cavity is further avoided, so that dirt can be discharged more effectively with the steam.

[0024] Preferably, the tobacco rod fits slightly within the oven cavity.

[0025] Preferably, the thicker portion comprises at least one layer of tipping paper.

[0026] With this arrangement, the user experience is further improved, as tipping paper is used without causing a paper smell, which is not the case with conventional solutions such as Figure 1 and Figure 2 In the solution shown in FIG. 1 , a paper smell is currently generated due to the air flowing against the tipping paper.

[0027] Preferably, the thickness of the layer of tipping paper is between 0.02 mm and 0.2 mm.

[0028] Preferably, the thicker portion comprises 1 to 10 layers of tipping paper.

[0029] This design of the thicker portion allows the tobacco rod to fit slightly into the oven cavity.

[0030] Preferably, the internal passage comprises a frustoconical recess having a smaller diameter end proximal to the bottom surface and a larger diameter end distal to the bottom surface.

[0031] It is also foreseeable that the cellulose acetate tube includes an array of perforations extending from a second front surface distal from the bottom surface toward a first front surface proximate to the bottom surface.

[0032] This design of the internal passage makes it possible to promote the distribution of air into the tobacco rod.

[0033] Preferably, the nozzle comprises a sliding member.

[0034] By doing this, a tobacco rod insertion sensor can be provided.

[0035] Preferably, the sliding member is ferromagnetic and the sensor comprises a Hall Effect sensor.

[0036] This design of the slide member and the sensor allows the tobacco rod insertion sensor to be arranged in a space-saving manner.

[0037] In another embodiment, the housing comprises an outer cavity, the oven cavity is located in the outer cavity so as to define a radial gap between the outer cavity and the oven cavity, and the aerosol generating system comprises an insulation layer arranged radially outside the oven cavity.

[0038] By doing so, condensation of the steam on the cylindrical surface of the oven cavity can be more effectively avoided. Dirt can thus be further discharged with the steam.

[0039] A battery volume and / or electronics unit is also foreseen, the housing including a second airflow path that continues to extend through the housing, the second airflow path being in fluid communication with the inlet of the first airflow path, at least a portion of the second airflow path being proximate to the battery volume and / or electronics unit.

[0040] By doing so, the airflow may be used to cool hot spots of the aerosol generating system, thereby enhancing the user's experience.

[0041] Preferably, the aerosol-generating system further comprises a flavour-receiving space proximate the bottom surface.

[0042] Such a flavour receiving space makes it possible to add flavour to the input air in a particularly easy manner, the user simply having to add flavour drops or flavour tablets to the bottom of the oven cavity. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Embodiments of the present invention will now be described with reference to the accompanying drawings, which are intended to better understand the concept of the present invention and should not be considered as limiting the present invention. In the accompanying drawings:

[0044] Figure 1 is a cross-sectional view of a conventional aerosol generating system.

[0045] Figure 2 yes Figure 1 Detailed cross-sectional view of the oven cavity of the aerosol generating system,

[0046] Figure 3 is a detailed cross-sectional view of an oven cavity of an aerosol generating system according to a first embodiment of the present invention,

[0047] Figure 4 yes Figure 3 Detailed perspective view of the cellulose acetate tube of the tobacco rod of the aerosol generating system of

[0048] Figure 5 is a perspective view of a nozzle of an aerosol generating system according to a second embodiment of the present invention,

[0049] Figure 6 is a perspective view of a nozzle of an aerosol generating system according to a third embodiment of the present invention,

[0050] Figure 7 is a perspective view of a nozzle of an aerosol generating system according to a fourth embodiment of the present invention,

[0051] Figure 8 is a cross-sectional view of an aerosol generating system according to a fifth embodiment of the present invention,

[0052] Fig. 9 is a cross-sectional view of an aerosol generating system according to a sixth embodiment of the present invention,

[0053] Fig.10 is a detailed cross-sectional view of an oven cavity of an aerosol generating system according to a seventh embodiment of the present invention,

[0054] Fig.11is a detailed cross-sectional view of an oven cavity of an aerosol generating system according to an eighth embodiment of the present invention,

[0055] Fig.12 is a detailed cross-sectional view of an oven cavity of an aerosol generating system according to a ninth embodiment of the present invention,

[0056] Fig.13 is a perspective view of a nozzle of an aerosol generating system according to a tenth embodiment of the present invention, and

[0057] Fig.14 is a detailed cross-sectional view of an oven cavity of an aerosol generating system according to an eleventh embodiment of the invention. DETAILED DESCRIPTION

[0058] Embodiments of the present invention will now be described with reference to the following drawings. The same reference numerals or similar reference numerals arranged in sequence are used throughout the drawings to indicate the same features and components.

[0059] Reference now Figure 3 , the aerosol generating system 2 comprises a housing 4 defining an oven cavity 6. In the depicted embodiment, the oven cavity 6 forms a cylinder of revolution. In the present specification, the words "axial" and "radial" and their derivatives will be understood to refer to a circular axial cross-section of the oven cavity 6. The oven cavity 6 comprises a cylindrical surface 8, a bottom surface 10 and an opening portion 12.

[0060] The housing 4 further comprises an outer cavity 14 having a cylindrical shape and an axial cross section of the outer cavity being larger than the axial cross section of the oven cavity 6. The oven cavity 6 is located inside the outer cavity 14. With this arrangement, a radial gap 16 is defined between the outer cavity 14 and the oven cavity 6.

[0061] A heat insulation layer 18 is arranged on the radial outer side of the oven cavity 6 to provide heat insulation between the oven cavity 6 and the radial gap 16 .

[0062] The aerosol generating system 2 further comprises a tobacco rod 20. The tobacco rod 20 is partially received in the oven cavity 6. The tobacco rod 20 comprises the following in order: a first end 22, an acetate tube 24, a body 26, and a second end 28. The first end 22 faces the bottom surface 10 of the oven cavity 6. The second end 28 is longitudinally opposite to the first end 22. The second end 28 is farther from the bottom surface 10 than the opening 12. In other words, the opening 12 is located between the end 22 and the end 28. The acetate tube 24 and the body 26 may be wrapped in a layer of tipping paper 29 ( Figure 4 can be seen in ).

[0063] The tobacco rod 20 includes a thicker portion 30 disposed between the first end 22 and the second end 28. In the depicted embodiment, the thicker portion 30 is adjacent to the second end 28 and is long enough to extend beyond the opening 12 away from the second end 28. In this way, undesirable secondary airflow between the tobacco rod 20 and the cylindrical surface 8 is avoided despite the depression created by suction at the bottom of the oven cavity 6.

[0064] In the depicted embodiment, the thicker portion 30 is a layer of plugging paper. The thickness of this layer of plugging paper 30 is between 0.02 mm and 0.2 mm. As an alternative, the thicker portion may include at least two layers of plugging paper, preferably between 1 and 10 layers of plugging paper 30.

[0065] Reference now Figure 4 , the acetate tube 24 includes an interior passage 32, a cylindrical surface 34 extending between a first front surface 36 and a second front surface 38. The first front surface 36 faces the bottom surface 10 of the oven cavity 6. The second front surface 38 is adjacent to the body 26 and is therefore farther from the bottom surface 10 than the first front surface 36.

[0066] In the first embodiment, the internal passage 32 extends between the first front surface 36 and the second front surface 38 .

[0067] The cellulose acetate tube 24 further includes at least one aperture 40 extending between the cylindrical surface 34 and the interior passage 32 .

[0068] The aerosol generating system 2 further comprises a nozzle 41 mounted on the bottom surface 10 of the oven cavity 6. More specifically, the nozzle 41 extends through the bottom surface 10, the insulation layer 18 and the first end 22 of the tobacco rod 20. Figure 3 As can be seen in FIG. 4 , the nozzle 41 extends in the inner channel 32 .

[0069] With this arrangement, the aerosol generating system 2 defines an upstream airflow path 42 and a downstream airflow path 44 .

[0070] The upstream airflow path 42 extends through the housing 4 upstream of the oven cavity 6. The upstream airflow path 42 includes an air inlet 46 formed by the opening portion of the outer cavity 14 and an air outlet 48 formed by the nozzle 41. Therefore, as the user draws on the tobacco stick 20, the air flowing along the upstream airflow path 42 passes through the opening portion of the outer cavity 14, enters the radial gap 16 extending between the cylindrical surface of the outer cavity 14 and the insulation layer 18, and reaches the nozzle 41.

[0071] The downstream airflow path 44 extends through the oven cavity 6 and the tobacco rod 20. The downstream airflow path 44 includes an inlet 50 corresponding to the nozzle 41 and an outlet 52 corresponding to the second end 28 of the tobacco rod 20. Therefore, the inlet 50 fluidly connects the downstream airflow path 44 with the upstream airflow path 42 located outside the oven cavity 6. The outlet 52 fluidly connects the downstream airflow path 44 with the outside of the tobacco rod 20. Therefore, as the user draws on the tobacco rod 20, the air flowing along the downstream airflow path 44 first flows through the nozzle 41, then through the internal channel 32 of the acetate tube 24, optionally through the orifice 40, and then through the heated tobacco particles of the body 26 of the tobacco rod 20. Finally, the air flowing along the downstream airflow path 44 flows through the outlet 52 formed by the second end 28 to be inhaled by the user.

[0072] Reference now Figure 5 , which depicts a nozzle 54 according to a second embodiment of the present invention. The nozzle 54 may be used in an aerosol generating system, such as the aerosol generating system 2 of the first embodiment of the present invention.

[0073] Like nozzle 41, nozzle 54 is mounted on the bottom surface 10 of oven cavity 6 and extends through the first end 22 of tobacco rod 20. More specifically, like nozzle 41, nozzle 54 enables fluid communication between the interior space of outer cavity 14 and the interior passage 32 of acetate tube 24 of tobacco rod 20.

[0074] The nozzle 54 includes a generally frustoconical outer surface 56. The outer surface 56 includes a longer diameter end 58 and a smaller diameter end 60. The nozzle 54 includes a first axial portion 62 adjacent to the longer diameter end 58, a second axial portion 64 adjacent to the smaller diameter end 60, and a third axial portion 66 located between the axial portions 62 and 64.

[0075] The first axial portion 62 extends through the bottom surface 10 of the oven cavity 6. In other words, the longer diameter end portion 58 is adjacent to the outer surface of the insulation layer 18. The boundary between the first axial portion 62 and the third axial portion 66 is adjacent to the bottom surface 10. The second axial portion 64 extends through the first end portion to penetrate the tobacco rod 20. In other words, the smaller diameter end portion 60 is inserted into the tobacco rod 20. More specifically, the smaller diameter end portion 60 is received in the inner passage 32 of the acetate tube 24. The boundary between the second axial portion 64 and the third axial portion 66 is adjacent to the first end portion 22 of the tobacco rod 20.

[0076] The nozzle 54 includes a plurality (eg, three) of circumferential ribs 68. The circumferential ribs 68 allow the nozzle 54 to be optimally fitted and sealed into the tobacco rod 20 to avoid undesirable secondary airflow by facilitating insertion of the tobacco rod 20.

[0077] The nozzle 54 comprises an inner through hole 70 forming the inlet 15. The inner through hole 70 forms a cylinder of revolution about the same axis of revolution as the frustoconical outer surface 56. In other words, the circular axial section of the inner through hole 70 and the circular axial section of the outer surface 56 are about the same axis.

[0078] The internal through hole 70 comprises an internal thread 72 which is capable of cooperating with an external thread provided integrally with the bottom surface 10. Alternatively or additionally, the tobacco rod 20 is integrally provided with an internal thread.

[0079] Reference now Figure 6 , which depicts a nozzle 74 according to a third embodiment of the present invention. The nozzle 74 may be used in an aerosol generating system, such as the aerosol generating system 2 of the first embodiment of the present invention.

[0080] In particular, like the nozzle 54, the nozzle 74 includes a generally frustoconical outer surface 56, a longer diameter end 58, a shorter diameter end 60, a first axial portion 62 extending through the bottom surface 10, a second axial portion 64 extending through the first end 22 to penetrate the tobacco rod 20, a third axial portion 66, and a cylindrical internal through hole 70.

[0081] The nozzle 74 differs from the nozzle 54 mainly in that the former includes ribs 76 extending in a direction forming a variable angle with respect to the circumferential direction of the outer surface 56. Furthermore, the nozzle 74 does not include internal threads on the inner surface of the through hole 70.

[0082] Reference now Figure 7 , which depicts a nozzle 78 according to a fourth embodiment of the present invention. The nozzle 78 may be used in an aerosol generating system, such as the aerosol generating system 2 of the first embodiment.

[0083] Like nozzles 54 and 74, nozzle 78 includes a generally frustoconical outer surface 56, a longer diameter end 58, a shorter diameter end 60, a first axial portion 62 extending through the bottom surface 10, a second axial portion 64 extending through the first end 22 to penetrate the tobacco rod 20, and a third axial portion 66. Like nozzles 54 and 74, nozzle 78 further includes an internal through hole 70, which is optionally provided with an internal thread 72.

[0084] like Figure 7 As can be seen in FIG. 5 , the nozzle 78 includes external threads 80 disposed on the wall length of the outer surface 56 .

[0085] Reference now Figure 8 , which depicts an aerosol generating system 81 according to a fifth embodiment of the present invention.

[0086] The aerosol generating system 81 comprises an electronic unit 82 and a battery volume 83 arranged inside the housing 4. More specifically, the electronic unit 82 is arranged below the oven cavity 6 and the battery volume 83 is arranged on the side opposite to the side containing the oven cavity 6.

[0087] In the fifth embodiment, the upstream airflow path 42 and the downstream airflow path 44 are illustrated by line 84. Figure 8 As can be seen in FIG. 4 , the upstream airflow path 42 continues to extend through the housing 4 between the air inlet 46 provided on the side surface of the housing 44 and the nozzle 41 . Furthermore, the upstream airflow path 42 includes a portion 85 close to the electronic unit 82 .

[0088] With this arrangement, the air inlet may be used to cool hot spots of the aerosol generating system 81 (such as the electronics unit 82 ).

[0089] Reference now Fig. 9 , which depicts an aerosol generating system 86 according to a sixth embodiment of the present invention.

[0090] Like the aerosol generating system 81, the aerosol generating system 86 comprises an electronic unit 82 and a battery volume 83. The main difference between the aerosol generating system 86 and the aerosol generating system 81 is that the air inlet 46 is arranged on the bottom surface of the housing 4. As a result, in addition to the portion 85 close to the electronic unit 82, the upstream airflow path 42 also includes a portion 87 close to the battery volume 83.

[0091] The air inlet may therefore cool another hot spot of the aerosol generating system 86 .

[0092] Reference now Fig.10 , which depicts an aerosol generating system 88 according to a seventh embodiment of the present invention.

[0093] The main difference between aerosol generating system 88 and aerosol generating system 2 is that the interior space of outer cavity 14 below bottom surface 10 includes flavor receiving space 89. The user can add flavor drops or flavor tablets to the flavor receiving space 89 to add flavor to the generated aerosol and further enhance the user's experience.

[0094] Reference now Fig.11 , which depicts an aerosol generating system 90 according to an eighth embodiment.

[0095] The main difference between the aerosol generating system 90 and the aerosol generating system 2 is that the internal passage 32 of the cellulose acetate tube 24 includes a frustoconical recess 91. The frustoconical recess 91 includes a smaller diameter end 92 and a larger diameter end 93. The smaller diameter end 92 is closer to the bottom surface 10 than the larger diameter end 93. The nozzle 41 is inserted through the smaller diameter end 92.

[0096] Reference now Fig.12 , which depicts an aerosol generating system 94 according to a ninth embodiment of the present invention.

[0097] The aerosol generating system 94 differs from the aerosol generating system 2 in that the internal passage is formed by an array of perforations 95. In addition, the aerosol generating system 94 comprises a plurality of nozzles 41, for example one nozzle 41 for each perforation 95. In the depicted embodiment, the perforations 95 extend from the second front surface 38 towards the first front surface 36. The perforations 95 communicate with the internal passage 32 at approximately halfway along the length of the acetate tube 24.

[0098] Reference now Fig.13 , which depicts a nozzle 96 according to a tenth embodiment. The nozzle 96 may be used in any of the aerosol generating systems 2, 81, 86, 88, 90 and 94.

[0099] like Fig.13 As can be seen in the figure, nozzle 96 is similar to nozzle 74 of the third embodiment and in particular comprises ribs 76 extending in a direction forming a variable angle with respect to the circumferential direction of outer surface 56. However, the shape of outer surface 56 and the shape of internal through hole 70 may be modified, for example by replacing the features of nozzles 54 and 78.

[0100] The nozzle 96 includes a sliding member 97 inserted into the through hole 70. The sliding member 97 can move inside the slot 70 in the axial direction of the nozzle 96. In the depicted example, the sliding member 97 is a spherical ball having a diameter slightly smaller than the diameter of the axial section of the through hole 70.

[0101] The nozzle 96 further comprises a coil spring 98. The coil spring 98 comprises a lower end 99 attached to the nozzle 96 and an upper end 100 attached to the slide member 97. The coil spring 98 is configured to work under compression, i.e., to work by pushing the slide member 97 in a direction extending from the lower longer diameter end 58 to the upper shorter diameter end 60. With this arrangement, when the tobacco rod 20 is inserted into the oven cavity 6, and when the nozzle 96 is properly inserted into the acetate tube 24, the slide member 97 is pushed towards the lower end 99, and the coil spring 98 is compressed. When the tobacco rod 20 is removed, the slide member 97 is no longer pushed by the tobacco rod 20 and resumes its rest position, adjacent to the shorter diameter end 60 and further from the lower end 99 than when pushed by the tobacco rod 20.

[0102] The nozzle 96 further includes a sensor 101. The sensor 101 is capable of detecting the position of the slide relative to the nozzle 96. More specifically, the sensor 101 can detect whether the slide 97 is adjacent to the shorter diameter end 60, such as Fig.13 As depicted in , or detecting whether the sliding component is in the compressed position of the coil spring 98, that is, the position close to the lower end 99 of the coil spring 98.

[0103] In this embodiment, the sliding member 97 is made of a ferromagnetic material and the sensor 101 is a Hall effect sensor.

[0104] Reference now Fig.14 , which points to an aerosol generating system 102 according to an eleventh embodiment of the present invention.

[0105] The aerosol generating system 102 differs from the aerosol generating system 2 in that the internal passage 32 comprises a non-through hole 104 extending from the first front surface 36 to the second front surface 38 of the acetate tube 24. The non-through hole 104 is in fluid communication with the orifice 40 of the acetate tube 24.

[0106] Thus, the main difference between the aerosol generating system 102 and the aerosol generating system 2 is that the hole forming the internal passage 32 does not extend over the length of the wall of the cellulose acetate tube 24 between the front surfaces 36 and 38. This arrangement allows further reduction of tobacco particles falling into the nozzle, thereby improving the consistency of the pressure drop in the aerosol generating system 102.

[0107] Although all detailed embodiments have been described, these embodiments are only intended for a better understanding of the invention defined by the independent claims and should not be considered as limiting.

Claims

1. An aerosol generating system (2, 81, 86, 88, 90, 94, 102), comprising: - a housing (4) defining an oven cavity (6) having a bottom surface (10) and an opening portion (12), - a tobacco rod (20) at least partially received in the oven cavity (6), the tobacco rod (20) having a first end (22) facing the bottom surface (10), and - a first airflow path (44) extending through the oven cavity (6) and the tobacco rod (20), the first airflow path (44) having an inlet (50) fluidly connecting the first airflow path (44) with the outside of the oven cavity (6) and an outlet (52) fluidly connecting the first airflow path (44) with the outside of the tobacco rod (20), the inlet (50) comprising a nozzle (41, 54, 74, 78, 96) mounted on the bottom surface (10) of the oven cavity (6) and extending through the first end (22), Characterized in that the tobacco rod (20) includes an acetate tube (24) adjacent to the first end (22), the acetate tube (24) including an internal passage (32), and the first airflow path (44) extends through the internal passage (32).

2. An aerosol generating system (2, 81, 86, 88, 90, 94, 102) according to claim 1, wherein The acetate tube (24) includes a first front surface (36), a second front surface (38), a cylindrical surface (34) extending between the first and second front surfaces (36, 38), and an orifice (40) extending between the cylindrical surface (34) and the interior passage (32).

3. An aerosol generating system (102) as claimed in claim 2, wherein: The first front surface (36) is close to the bottom surface (10) and the second front surface (38) is far from the bottom surface (10), and the internal channel (32) includes a blind hole (104) extending from the first front surface (36).

4. An aerosol generating system (2, 81, 86, 88, 90, 94, 102) according to any one of claims 1 to 3, wherein: The nozzle (41, 54, 74, 78, 96) includes a generally frustoconical outer surface (54), a first axial portion (62) extending through the bottom surface (10), and a second axial portion (64) extending through the first end (22) to penetrate the tobacco rod (20), the first axial portion (62) being proximate to a longer diameter end (58) of the generally frustoconical outer surface (54), and the second axial portion (64) being proximate to a shorter diameter end (60) of the generally frustoconical outer surface (54).

5. An aerosol generating system (2, 81, 86, 88, 90, 94, 102) according to any one of claims 1 to 4, wherein: The generally frustoconical outer surface (54) includes a plurality of circumferential ribs (68).

6. An aerosol generating system (2, 81, 86, 88, 90, 94, 102) according to any one of claims 1 to 5, wherein: The generally frustoconical outer surface (54) includes external threads (80).

7. An aerosol generating system (2, 81, 86, 88, 90, 94, 102) according to any one of claims 1 to 6, wherein: The nozzle (41, 54, 74, 78, 96) includes a cylindrical inner through-hole (70) having a circular axial cross-section.

8. An aerosol generating system (2, 81, 86, 88, 90, 94, 102) according to any one of claims 1 to 7, wherein: The cylindrical inner through hole (70) includes an internal thread (72).

9. An aerosol generating system (2, 81, 86, 88, 90, 94, 102) according to any one of claims 1 to 8, wherein: The tobacco rod (20) includes a second end (28) longitudinally opposite to the first end (22) and a thicker portion (30) between the first end (22) and the second end (28).

10. An aerosol generating system (2, 81, 86, 88, 90, 94, 102) according to claim 9, wherein The thicker portion (30) comprises at least one layer of tipping paper.

11. An aerosol generating system (2, 81, 86, 88, 90, 94, 102) according to claim 7, wherein: The thickness of the layer of tipping paper (30) is between 0.02 mm and 0.2 mm.

12. An aerosol generating system (2, 81, 86, 88, 90, 94, 102) according to any one of claims 1 to 11, wherein The thicker portion (30) comprises 1 to 10 layers of tipping paper.

13. An aerosol generating system (90) as claimed in any one of claims 1 to 12, wherein: The internal passage (32) includes a frustoconical recess (91) having a smaller diameter end (92) proximal to the bottom surface (10) and a larger diameter end (93) distal to the bottom surface (10).

14. An aerosol generating system (94) as claimed in any one of claims 1 to 13, wherein: The cellulose acetate tube (24) includes an array of perforations (95) extending from a second front surface (38) distal from the bottom surface (10) to a first front surface (36) proximate to the bottom surface (10).

15. An aerosol generating system (2, 81, 86, 88, 90, 94, 102) according to any one of claims 1 to 14, wherein The nozzle (96) includes: a sliding member (97) capable of moving along the longitudinal direction of the nozzle (96); a spring (98) configured to move the sliding member (97) in a direction extending from the bottom surface (10) toward the opening portion (12); and a sensor (101) capable of detecting the position of the sliding member (97).

16. An aerosol generating system (2, 81, 86, 88, 90, 94, 102) according to claim 15, wherein The sliding member (97) is ferromagnetic and the sensor (101) comprises a Hall effect sensor.

17. An aerosol generating system (2, 81, 86, 88, 90, 94, 102) according to any one of claims 1 to 16, wherein: The housing (4) comprises an outer cavity (14), the oven cavity (6) is located in the outer cavity (14) to define a radial gap (16) between the outer cavity (14) and the oven cavity (6), and the aerosol generating system (2, 81, 86, 88, 90, 94, 102) comprises a heat insulation layer (18) arranged radially outside the oven cavity (4).

18. An aerosol generating system (81, 86) as described in any one of claims 1 to 17, the aerosol generating system further comprising a battery volume (83), the housing (4) comprising a second airflow path (42) that continues to extend through the housing (4), the second airflow path (42) being fluidically connected to the inlet (52) of the first airflow path (50), and at least a portion (85, 87) of the second airflow path (42) being close to the battery volume (83).

19. An aerosol generating system (81, 86) as described in any one of claims 1 to 18, the aerosol generating system further comprising an electronic unit (82), the housing (4) comprising a second airflow path (42) that continues to extend through the housing (4), the second airflow path (42) being fluidically connected to the inlet (52) of the first airflow path (50), and at least a portion (85, 87) of the second airflow path (42) being close to the electronic unit (82).

20. An aerosol generating system (88) as claimed in any one of claims 1 to 19, further comprising a flavour receiving space (89) proximate to the bottom surface (10).

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