AEROSOL-GENERATING DEVICE COMPRISING A CHAMBER FOR RECEIVING AN AEROSOL-GENERATING ARTICLE

Abstract

An aerosol-generating device (100) for use with an aerosol-generating article comprises a chamber (121) for removably receiving at least a portion of the aerosol-generating article. Along a center axis (122) of the chamber (121), an inner surface (130) of the chamber (121) comprises a first axial portion (131) and a second axial portion (132), wherein the first axial portion (131) is closer to a proximal end (124) of the chamber (121) than the second axial portion (132). The second axial portion (132) is dimpled comprising a plurality of indentations (142), wherein the plurality of indentations (142) extend from a base level area of the second axial portion (142) outwards in a direction away from the center axis (122). The first axial portion (131) comprises a plurality of first protrusions (141), wherein the plurality of first protrusions (141) are configured to contact at least a portion of the aerosol-generating article when the article is received in the chamber (121), and wherein the plurality of first protrusions (141) extend from abase level area of the first axial portion (131) in a direction towards the center axis (122) beyond the base level area of the second axial portion (132).

Claims

1. Aerosol-generating device for use with an aerosol-generating article, the aerosol-generating device comprising a chamber for removably receiving at least a portion of the aerosol-generating article, wherein along a center axis of the chamber, an inner surface of the chamber comprises a first axial portion and a second axial portion, wherein the first axial portion is closer to a proximal end of the chamber than the second axial portion, wherein the second axial portion is dimpled comprising a plurality of indentations, wherein the plurality of indentations are punctiform and extend from a base level area of the second axial portion outwards in a direction away from the center axis, and wherein the first axial portion comprises a plurality of first protrusions, wherein the plurality of first protrusions are configured to contact at least a portion of the aerosol-generating article received in the chamber, and wherein the plurality of first protrusions extend from a base level area of the first axial portion in a direction towards the center axis beyond the base level area of the second axial portion.

2. Aerosol-generating device according to claim 1, wherein, along the center axis of the chamber, the inner surface of the chamber comprises a third axial portion, wherein the third axial portion is closer to a distal end of the chamber than the second axial portion, wherein the third axial portion comprises a plurality of second protrusions, wherein the plurality of second protrusions are configured to contact at least a portion of the aerosol-generating article received in the chamber, wherein the plurality of second protrusions extend from a base level area of the third axial portion in a direction towards the center axis, beyond the base level area of the second axial portion.

3. Aerosol-generating device according to claim 1, wherein at least one of the plurality of indentations has a conical shape or a frusto-conical shape or a pyramidal shape or a pimple-shape or a frusto-pyramidal shape or a dome-shape or a cuboid-shape or a partially spherical shape or a cylindrical shape or a trihedral shape or a polyhedral shape.

4. Aerosol-generating device according to claim 1, wherein an opening area of at least one of the plurality of indentations has a circular shape or an oval shape or an elliptical shape or a rectangular shape or a quadric shape or a rhombus shape or a parallelogram shape or triangular shape or a hexagonal shape or polygonal shape.

5. Aerosol-generating device according to claim 1, wherein a density of the plurality of indentations is in a range between 0.1 and 1.0 indentations per square millimeter.

6. Aerosol-generating device according to claim 1, wherein at least one of the plurality of indentations has a depth dimension in a direction normal to an opening area of the respective indentation in a range between 0.25 millimeter and 2 millimeter.

7. Aerosol-generating device according to claim 2, wherein each one of the base level area of the second axial portion, the base level area of the first axial portion and the base level area of the third axial portion is a coherent area.

8. Aerosol-generating device according to claim 1, wherein the base level area of the second axial portion has a hexagonal grid pattern.

9. Aerosol-generating device according to claim 2, wherein at least one of the base level area of the first axial portion and the base level area of the third axial portion has a crisscross grid pattern.

10. Aerosol-generating device according to claim 1, wherein the second axial portion has a length of at least 20 percent of an overall length of the inner surface or the chamber in the direction of the center axis.

11. Aerosol-generating device according to claim 2, wherein at least one, or each one of the plurality of first protrusions has a conical shape or a frusto-conical shape or a pyramidal shape or a pimple-shape or a frusto-pyramidal shape or a dome-shape or a cuboid-shape or a partially spherical shape or a cylindrical shape or a trihedral shape or a polyhedral shape; or wherein at least one, or each one of the optional plurality of second protrusions has a conical shape or a frusto-conical shape or a pyramidal shape or a pimple-shape or a frusto-pyramidal shape or a dome-shape or a cuboid-shape or a partially spherical shape or a cylindrical shape or a trihedral shape or a polyhedral shape.

12. Aerosol-generating device according to claim 2, wherein at least one of a density of the plurality of first protrusions and a density of the optional plurality of second protrusions is in a range between 0.25 and 1.5 protrusions per square millimeter.

13. Aerosol-generating device according to claim 2, wherein at least one, or each one of the plurality of first protrusions has a height dimension in a range between 0.5 millimeter and 2 millimeter, or at least one, or each one of the plurality of second protrusions has a height dimension in a range between 0.5 millimeter and 2 millimeter.

14. An aerosol-generating system comprising an aerosol-generating device according to claim 2 and an aerosol-generating article comprising an aerosol-forming substrate, wherein at least a portion of the aerosol-generating article is removably received or removably receivable in the chamber of the aerosol-generating device.

15. The aerosol-generating system according to claim 14, wherein the aerosol-generating article comprises at least a proximal support element, and optional distal support element and a substrate element comprising the aerosol-forming substrate, the substrate element being located downstream the proximal support element and upstream the optional distal support element with regard to an airflow passing through the article in use of the system, wherein upon receiving the article in the chamber the proximal support element is in contact with the first axial portion, the optional third axial portion is in contact with the optional distal support element, and the substrate element is surrounded by the second axial portion without being in contact with the second axial portion.

16. Aerosol-generating device according to claim 1, wherein a density of the plurality of indentations is in a range between 0.2 and 0.7 indentations per square millimeter.

17. Aerosol-generating device according to claim 1, wherein at least one of the plurality of indentations has a depth dimension in a direction normal to an opening area of the respective indentation in a range between 0.5 millimeter and 1 millimeter.

18. Aerosol-generating device according to claim 2, wherein at least one of a density of the plurality of first protrusions and a density of the optional plurality of second protrusions is in a range between 0.5 to 0.75 protrusions per square millimeter.

19. Aerosol-generating device according to claim 2, wherein at least one, or each one of the plurality of first protrusions has a height dimension in a range between 0.75 millimeter and 1.5 millimeter; or at least one, or each one of the plurality of second protrusions has a height dimension in a range between 0.75 millimeter and 1.5 millimeter.

20. Aerosol-generating device according to claim 2, wherein at least one, or each one of the plurality of first protrusions has a height dimension in a range between 0.75 millimeter and 1.5 millimeter; and at least one, or each one of the plurality of second protrusions has a height dimension in a range between 0.75 millimeter and 1.5 millimeter.

Description

[0141] Examples will now be further described with reference to the figures in which:

[0142] FIG. 1 schematically illustrates in a sectional view an exemplary embodiment of an aerosol-generating system according to the present invention comprising aerosol-generating device and an aerosol-generating article;

[0143] FIG. 2 schematically illustrates the aerosol-generating system according to FIG. 1 without the article;

[0144] FIG. 3 schematically illustrates a chamber module of the device according to FIG. 1 in a perspective view;

[0145] FIG. 4 schematically illustrates the chamber module according to FIG. 3 in a sectional view; and

[0146] FIG. 5-7 schematically illustrate different embodiments of, respectively, the first, second and third axial portion of the inner surface of the chamber of the device according to FIG. 1.

[0147] FIG. 1 and FIG. 2 schematically illustrate an exemplary embodiment of an aerosol-generating system 1 according to the present invention. The system 1 comprises two main components: an aerosol-generating article 200 and an aerosol-generating device 100 for use with the article 200 in order to generate an inhalable aerosol by heating an aerosol-forming substrate 222 comprised within the article 200.

[0148] The aerosol-generating device 100 has an elongated shape and comprises a main body 110 and a sleeve-shaped chamber module 120. The chamber module 120 comprises a chamber 121 for receiving at least a portion of the aerosol-generating article 200. The chamber module 120 is inserted into a cavity 111 formed within a proximal portion 112 of the main body 110. Within a distal portion 113, the main body 110 comprises a power source 150 and a controller 160 for powering and controlling operation of the device 100.

[0149] The article 200 has a rod shape resembling the shape of a conventional cigarette. In the present embodiment, the article 200 comprises five elements arranged in coaxial alignment: a distal support element 210, a substrate element 220, a proximal support element 230, an aerosol-cooling element 240, and a filter plug 250. The distal support element 210 is arranged at a distal end of the article 200. The substrate element 220 comprises the aerosol-forming substrate 222 to be heated. The aerosol-forming substrate 22 may include, for example, a crimped sheet of homogenized tobacco material including glycerin as an aerosol-former. The proximal support element 230 comprises a hollow core forming a central air passage 232. The filter plug 250 serves as a mouthpiece and may include, for example, cellulose acetate fibers. The five elements are substantially cylindrical elements being arranged sequentially one after the other. The elements have substantially the same diameter and are circumscribed by an outer wrapper 260 made of cigarette paper such as to form a cylindrical rod. The outer wrapper 260 may be wrapped around the aforementioned elements so that free ends of the wrapper overlap each other. The wrapper may further comprise adhesive that adheres the overlapped free ends of the wrapper to each other.

[0150] For heating the substrate 222 within the article 200, the aerosol-generating device 100 according to the present invention comprises an inductive heating device. The inductive heating device comprises an induction coil 170 for generating an alternating, in particular high-frequency magnetic field within the chamber 121. Preferably, the high-frequency magnetic field may be in the range between 500 kHz (kilo-Hertz) to 30 MHz (Mega-Hertz), in particular between 5 MHz (Mega-Hertz) to 15 MHz (Mega-Hertz), preferably between 5 MHz (Mega-Hertz) and 10 MHz (Mega-Hertz). In the present embodiment, the induction coil 170 is a helical coil circumferentially surrounding the cylindrical chamber module 120 along its length axis 122. The alternating magnetic field is used for in inductively heating a susceptor 270 that is arranged within the aerosol-forming substrate 222 of the article 200 such as to experience the magnetic field generated by the induction coil 170 when the article 200 is received in the chamber 121. In the present embodiment, the susceptor 270 is a susceptor blade that is arranged within the substrate element 220 along the length axis of the article 200 such as to be in direct physical contact with aerosol-forming substrate 222.

[0151] Accordingly, when the inductive heating device is actuated, a high-frequency alternating current is passed through the induction coil 170 causing the alternating magnetic field to be generated within the chamber 121. Depending on the magnetic and electric properties of the respective susceptor material, the alternating magnetic field induces at least one of eddy currents or hysteresis losses in the susceptor 270. As a consequence, the susceptor 270 is heated up until reaching a temperature that is sufficient to form an aerosol from the substrate 222. The generated aerosol may be drawn downstream through the aerosol-generating article 200 for inhalation by the user.

[0152] FIG. 3 and FIG. 4 illustrate further details of the chamber module 120 and the chamber 121 which is defined by the walls of the chamber module 120. The chamber module 120 is an elongated sleeve comprising an insertion opening 126 through which the aerosol-generating article 200 may be inserted into the chamber 121 at the proximal end 101 of the device 100. The insertion direction of the aerosol-generating article 200 substantially extends along a center axis 122 of the chamber 121. The chamber module 120 is made of PEEK (polyether ether ketone). In the present embodiment, the chamber 121 has a substantially cylindrical shape with a substantially circular cross-section having a diameter of about 15 millimeter. The cylindrical shape and the circular cross-section of the chamber 121 substantially correspond to the cylindrical shape and the circular cross-section of the aerosol-generating article 200.

[0153] The chamber 121 comprises an inner surface 130 which extends over the entire axial length of the chamber 121. In the present embodiment, the axial length of the chamber 121 is in range of 25 millimeter to 28 millimeter. Along the center axis 122 of the chamber 121, the inner surface 130 comprises a first axial portion 131, a second axial 132 portion and a third axial portion 133, wherein the first axial portion 131 is closer to a proximal end 124 of the chamber 121 than the second axial portion 132 and the third axial portion 133 is closer to a distal end 123 of the chamber 121 than the second axial portion 132. Accordingly, the second axial portion 132 is located between the first axial portion 131 and the third axial portion 133. The length of the second axial portion 132 is of about 33 percent (about one third) of the axial length 129 of the chamber 121. The same holds for the length of the first axial portion 131. In contrast, the length of the third axial portion 133 is slightly shorter than the lengths of the first and second axial portions 131, 132.

[0154] The first axial portion 131 comprises a plurality of first protrusions 141 which extend from a base level area 145 of the first axial portion 131 in a direction towards the center axis 122 beyond a base level area 146 of the second axial portion 132. Likewise, the third axial portion 133 comprises a plurality of second protrusions 143 which extend from a base level area 147 of the third axial portion 133 in a direction towards the center axis 122 beyond the base level area 146 of the second axial portion 132. In contrast to the first and the third axial portions 131, 133, the second axial portion 132 does not comprise any protrusions. Instead, the second axial portion 132 is dimpled comprising a plurality of indentations 142 which extend from the base level area 146 of the second axial portion 132 outwards in a direction away from the center axis 122.

[0155] Hence, when an article 200 is inserted into the chamber 121, the article 200 is only in contact with the plurality of first protrusions 141 and the plurality of second protrusions 143. In contrast, the article 200 is not in contact with the second axial portion 132 of the inner surface 130. As a result, the overall contact area between the article 200 and the inner surface 130 of the chamber 121 is significantly reduced. Advantageously, this leads to an overall reduction of heat losses due to direct thermal conduction from the aerosol-generating article 200 to the inner surface 130. Furthermore, adverse moistening effects on the article 200 due to condensate formation in the chamber 121 are reduced as well. In addition, the reduced contact surface area makes insertion and removal of the article 200 easier, as the reduced contact surface area reduces the frictional forces to be overcome when moving an article 200 into or out of the chamber 121.

[0156] Notwithstanding the reduced contact area between the article 200 and the inner surface 130, the article 200 is still securely retained in the chamber 121 by the first and second protrusions 131, 132. In the present embodiment, this applies all the more as the arrangement and the dimensions of the first, second and third axial portions 131, 132, 133 are adapted to the arrangement and the dimensions of the proximal support element 230, the substrate element 220 and the distal support element 210. As can be seen in FIG. 1, when the article 200 is received in the chamber 121, the proximal support element 230 is in contact with the first protrusions 141 of the first axial portion 131 and the distal support element 210 is in contact with the second protrusions 143 of the third axial portion 133. In contrast, the substrate element 220 substantially is surrounded by the second axial portion 132, however, without any contact thereto. Only at its very axial ends, the substrate element 220 is partially in contact with the first protrusions 141 of the first axial portion 131 and the second protrusions 143 of the third axial portion 133. However it will be appreciated that in alternative embodiments, even the very axial ends may not be in contact with the protrusions 141, 143 or the first and third axial portions 131, 133 and instead the entire substrate element 220 may be within the second axial portion 132. Due to these specific configurations, the first and second protrusions 141, 143 of the first and the second axial portion 131, 133 substantially only engage with those portions of the article 200 which are most rigid and which tend to shrink least during use.

[0157] Furthermore, with reference to FIG. 1, the free space in between the first and the second protrusions 141, 143 forms a multi-dimensional matrix of airflow passages allowing air to flow between inner surface 130 of the chamber 121 and the outer surface of an aerosol-generating article 200 inserted in the chamber 121. Hence, when a negative pressure is applied at the filter element 250 of the aerosol-generating article 200 received in the receiving chamber 121, for example, when a user takes a puff, air is drawn into the receiving chamber 121 at the rim of the insertion opening 126, at the proximal end 101 of the device 100 or the proximal end 124 of the chamber 121, respectively. This airflow further passes along the inner surface 130 along the multi-channel airflow passages into the bottom portion at the distal end 123 of the receiving chamber 121. There, the airflow enters the aerosol-generating article 200 through the distal support element 210 and further passes through the substrate element 220, the proximal support element 230, the aerosol cooling element 240 and the filter element 250 where it finally exits the article 200. In the substrate element 240, vaporized material from the aerosol-forming substrate is entrained into the airflow and subsequently cooled down on its further way through the proximal support element 230, the aerosol cooling element 240 and the filter element 250 such as to form an aerosol. In order to enable a proper redirection of the airflow into the aerosol-generating article 200 at the distal end 123 of the receiving chamber 121, the aerosol-generating device 100 according to the present embodiment comprises end stops 128 which are arranged at the distal end 123 of the receiving chamber 121. The end stops 128 are configured to limit the insertion depth of the article 200 into the receiving chamber 121 and, thus, to prevent the article 200 from abutting the bottom surface of the receiving chamber 121. This is shown in FIG. 1.

[0158] With respect to the airflow passing along the inner surface 130 from the proximal end 124 of the chamber 121 towards the distal end 123 of the chamber 121, the plurality of indentations 142 in the second axial portion 132 causes the airflow along the second axial portion 132 to be turbulent. Advantageously, the turbulent airflow improves the airflow management through the device 100 and in particular ensures a sufficient heat exchange between air flowing around the article. Furthermore, the dimples 142 of the second axial portion 132 advantageously promote turbulent airflow in the region of the second axial portion 132, which helps to provide improved aerosol characteristics compared to conventional aerosol-generating systems

[0159] In the present embodiment, the first and the second protrusions 141, 143 are formed as punctiform protrusions having a pimple-shape. The first and the second protrusions 141, 143 are arranged in a regular matrix pattern. In contrast, the plurality of indentations 142 have a cylindrical shape with a hexagonal cross-section. That is, the opening area of each indentation 142 has a hexagonal shape or hexagonal cross-section. The indentations 142 are arranged in a hexagonal pattern, in particular a honeycomb configuration. Accordingly, the base level area 146 of the second axial portion 132 has a hexagonal grid pattern, in particular a honeycomb pattern.

[0160] Both, the base level areas of the first and third axial portions 131, 133 and the base level area of the second axial portion are coherent areas having no isolated sections.

[0161] As can be in particular seen in FIG. 4, the first and the second protrusions 141, 143 have the same height dimension 148. Likewise, all indentations 142 have the same depth dimension 149. With regard to a good airflow management, the height dimension 148 preferably is in a range between 0.5 millimeter and 2 millimeter, in particular in a range of 0.75 millimeter and 1.5 millimeter, as measured in a radial direction towards the center axis 122. Likewise, the indentations 142 preferably have a depth dimension 149 in a direction normal to the opening area of the respective indentation in a range between 0.25 millimeter and 2 millimeter, preferably in a range between 0.5 millimeter and 1 millimeter.

[0162] The formation of a turbulent airflow can also be influenced by the density of the indentations 147. Preferably, a density of the plurality of indentations 147 is in a range between 0.1 and 1.0 indentations per square millimeter, preferably between 0.2 and 0.7 indentations per square millimeter. Likewise, a density of the plurality of first protrusions and second protrusions 141, 143 is in a range between 0.25 and 1.5 protrusions per square millimeter, in particular between 0.5 to 0.75 protrusions per square millimeter. As used herein, the density per square millimeter is referenced to the area content of the projection of the respective axial portion 131, 132, 133 onto its base level area in direction normal to the base level area, that is, to an envelope surface tangent to each point of the respective base level area 145, 146, 147 as indicated in FIG. 4 by the dashed lines 191, 192. In the present embodiment, the density of the plurality of first protrusions 141 and the density of the plurality of second protrusions 143 are identical, but lower than the density of the plurality of indentations 147.

[0163] FIG. 5 and FIG. 6 schematically illustrate a respective section of alternative embodiments of the first and third axial portion of inner surface 231, 233, 331, 333. In FIG. 5, the first and the second protrusions 241, 243 have a cuboid-shape and arranged in a regular square pattern. Accordingly, the respective base level areas 245, 247 has regular square grid pattern. In FIG. 6, the first and the second protrusions 341, 343 have a pyramidal shape. The respective base level areas 345, 347 have a crisscross grid pattern such as to provide linear airflow passages between the first and second protrusions 341, 343, respectively.

[0164] FIG. 7 shows an alternative embodiment of the second axial portion 432. Here, the second axial portion 432 comprises plurality of indentations 442 each of which has a partially spherical shape, with a circular cross-section. That is, the opening area of each indentation 442 has a circular shape or circular cross-section. The indentations 442 are arranged in a square grid pattern.

[0165] For the purpose of the present description and of the appended claims, except where otherwise indicated, all numbers expressing amounts, quantities, percentages, and so forth, are to be understood as being modified in all instances by the term “about”. Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein. In this context, therefore, a number A is understood as A±5 percent of A.