Aerosol generating device configured to operate with flat-shaped tobacco articles and assembly containing such aerosol generating device

Abstract

The aerosol generating device (11) includes a flat heating chamber (38) that extends along the longitudinal axis (Y) of the device between a proximal end configured to operate with a flat tobacco article and to receive at least the tobacco portion (15) of the flat tobacco article and a distal end (42) opposite to the proximal end, the aerosol generating device (11) includes a rear portion (54) that extends between the distal end (42) of the flat heating chamber (38) and the distal wall (50) of the device housing (34), the rear portion (54) defining a single inlet channel (56) configured to provide airflow into the heating chamber (38), the single inlet channel (56) extending along the longitudinal axis (Y) of the device and having multiple cross-sections.

Description

Technical Field

[0001] The present invention relates to an aerosol generating device configured to operate with a tobacco article having a flat shape. The aerosol generating device includes a flat heating chamber. The present invention further relates to an aerosol generating assembly including the aerosol generating device and a tobacco article having a flat shape.

[0002] Specifically, the tobacco article having a flat shape includes, for example, a solid substrate that can form an aerosol when heated. Therefore, such a type of aerosol generating device, also known as a heat-not-burn device, is adapted to heat the substrate by conduction, convection and / or radiation rather than burn it to generate an aerosol for inhalation.

Background Art

[0003] (Also known as a vaporizer) The popularity and use of risk reduction devices or risk modification devices have been rapidly increasing in recent years as an aid to assist habitual smokers who wish to quit smoking conventional tobacco products such as cigarettes, cigars, cigarillos and roll-your-own tobacco. In contrast to burning tobacco in conventional tobacco products, various devices and systems for heating or warming a vaporizable substance are available.

[0004] Commonly available risk reduction or risk modification devices are substrate-heated aerosol generators or heated non-combustion devices. These types of devices typically generate aerosols or vapors by heating an aerosol substrate, usually containing moist tobacco leaves or other suitable vaporizable material, to a temperature typically in the range of 150°C to 350°C. By heating the aerosol substrate rather than burning or incinerating it, an aerosol is released that contains the components desired by the user but does not contain toxic and carcinogenic by-products from combustion and burning. Furthermore, aerosols produced by heating tobacco or other vaporizable materials typically do not contain the burnt or bitter taste that can be unpleasant to the user, and therefore the substrate does not require sugars and other additives that are typically added to such materials to make the smoke and / or vapor more palatable to the user.

[0005] Aerosol generating devices and their heating chambers may exhibit different shapes or geometric forms. Depending on the shape, the airflow through the device may differ at various points within the device. As a result, for example, the generated aerosol may accumulate at certain edges within the device. In particular, in some devices, certain parts of the tobacco article may be subject to higher vapor extraction compared to other parts, because a larger volume of air passes through those parts. Therefore, a large amount of aerosol may be extracted from the tobacco article in some areas, while only a small amount may be extracted in other areas, which may lead to, for example, suboptimal consumption of the tobacco article. This can affect the user experience and user comfort.

[0006] Therefore, some known aerosol generating devices can still be improved from the standpoint of user comfort. [Overview of the project] [Problems that the invention aims to solve]

[0007] One of the objectives of the present invention is to provide an aerosol generating device configured to operate with flat-shaped tobacco articles, which enables improved user comfort and, in particular, improved airflow through flat-shaped tobacco articles. [Means for solving the problem]

[0008] For this purpose, the present invention provides an aerosol generating device comprising a flat heating chamber extending along the longitudinal axis of the device between a proximal end configured to operate with a flat tobacco article and to receive at least the tobacco portion of the flat tobacco article, and a distal end opposite to the proximal end, The heating chamber has a flat shape and includes a rear portion extending between the distal end and the distal wall of the device housing, the rear portion defining a single inlet channel configured to provide airflow into the heating chamber. The present invention relates to an aerosol generating device in which a single inlet channel extends along the longitudinal axis of the device and has multiple cross-sections perpendicular to the longitudinal axis of the device, and at least one of the multiple cross-sections is substantially rectangular and has a shape substantially equal to the cross-section of a tobacco portion adjacent to the at least one cross-section.

[0009] These features improve user comfort because a single inlet channel exhibits a substantially rectangular cross-section substantially equal to the cross-section of the cigarette. This makes it possible to improve the airflow through a device having a flat heating chamber configured to accept a flat-shaped cigarette article. In fact, these features allow the airflow through the inlet channel to be laminar with little or no turbulence. Thus, aerosol removal can be improved over the entire surface of the cigarette article. Additionally, these features make it possible to reduce negative pressure pockets that can lead to condensation within the heating chamber. In fact, laminar airflow reduces such condensation. In contrast to these features, the airflow can be turbulent in the case of a transition from an inlet channel having a circular cross-section at a transition point where it joins a flat-shaped heating chamber. Such a transition point between the circular cross-section and the flat shape of the heating chamber can lead to reduced aerosol removal and / or condensation formation within the heating chamber or at the transition point between the single inlet channel and the heating chamber, in contrast to the features of the aerosol generating device according to this disclosure.

[0010] In particular, at least one cross-section has a shape substantially identical to the cross-section of the tobacco portion adjacent to this cross-section, thereby facilitating a smooth transition of airflow between the single inlet channel and the distal end of the heating chamber. Preferably, the shape of the inlet channel may match the shape of the tobacco article with which it comes into contact.

[0011] Preferably, a single inlet channel may be formed such that the airflow can adhere to the side walls of the inlet channel. In particular, a single inlet channel may have a shape that, due to the Coanda effect, can increase the airflow close to the walls of the inlet channel compared to the central region of the inlet channel. Such a shape may be, for example, a curved inner side wall of the inlet channel. In another example, the inlet channel may be bounded by, for example, a straight side wall that extends parallel to the longitudinal axis of the device or according to a certain angle formed between the wall and the longitudinal axis of the device. In this case, to obtain the Coanda effect, for example, the inlet channel may have a curved transition from the outer surface of the device to the straight side wall. In particular, the Coanda effect here describes the tendency of airflow or jets to remain adhered to convex surfaces, such as the walls of the inlet channel. Naturally, different shapes of a single inlet channel may be combined according to the example.

[0012] An inlet channel configured to provide an airflow adhering to the walls of the inlet channel allows a large volume of air to be supplied to the outer surface of a tobacco article extending parallel to the longitudinal axis of the device. This makes it possible to generate a large amount of aerosol on the outer surface of the tobacco article. This can be particularly advantageous when the tobacco article has a high tobacco density, as this reduces the likelihood of airflow being generated through the tobacco. In particular, in this case, the aerosol can be generated mainly on the outer surface of the tobacco article, and this aerosol generation is facilitated by the characteristics of the inlet channel.

[0013] The expression "single inlet channel" is understood to mean that the rear portion of the device has only one inlet channel configured to supply air into the heating chamber. In particular, the rear portion, especially the distal wall, may have only one opening. Specifically, the device as a whole may have only one air inlet into the heating chamber, i.e., a single inlet channel. For example, the device may have one inlet channel at the distal end for receiving air into the heating chamber and further have an air outlet at the proximal end configured to supply an airflow containing aerosols to the user. In other examples, the device may have additional inlets in the side walls of the device.

[0014] The phrase "cross section perpendicular to the longitudinal axis of the device" implies that the corresponding cross section extends along a plane positioned perpendicular to the longitudinal axis of the device.

[0015] For example, the cross-section of the inlet channel adjacent to the tobacco cross-section may have a height of substantially equal to 1.2 mm and / or a width of substantially equal to 11.5 mm.

[0016] According to some embodiments, a single inlet channel may be bounded along the longitudinal axis of the device by a channel inlet cross section defining an air inlet and a channel outlet cross section adjacent to the heating chamber, the channel outlet cross section having a substantially rectangular shape.

[0017] Due to these characteristics, the airflow is laminar, particularly in the transition between the inlet channel and the heating chamber, as the outlet cross-section has a substantially rectangular shape and is therefore adapted to the flat shape of the heating chamber.

[0018] According to some embodiments, a single inlet channel is bounded by at least one inner surface in a direction perpendicular to the longitudinal axis of the device, the inner surface connecting the channel inlet cross section to the channel outlet cross section, and the inner surface forming an angle of less than 90° with the longitudinal axis of the device at each point.

[0019] These characteristics allow the airflow to undergo a decrease in velocity or turbulence, and in particular, to easily pass through the inlet channel without contacting obstacles such as internal steps.

[0020] According to some embodiments, the inner surface exhibits a smooth transition between the channel inlet cross-section and the channel outlet cross-section.

[0021] These features result in an airflow guided by the inlet channel between the inlet and outlet cross-sections that generates little to no turbulence, leading to improved steam extraction within the heating chamber. In addition, the inlet channel can be manufactured simply and quickly.

[0022] According to some embodiments, at least one inner surface defines at least one straight line that connects an edge of a substantially rectangular shape of the flow path outlet cross-section to the flow path inlet cross-section.

[0023] These features enable the inlet flow path to supply a laminar air flow to the tobacco article as the inlet flow path moves linearly or straightly from the flow path inlet cross-section towards the tobacco portion. For example, the inlet flow path enables the air flow to be directed parallel to a straight line such that only a very slight turbulence of the air flow is generated. The straight lines may extend parallel to each other along the longitudinal axis of the device or may exhibit a decreasing distance from each other.

[0024] According to some embodiments, the maximum width of a single inlet flow path at the flow path inlet cross-section is smaller than the maximum width of a single inlet flow path at the flow path outlet cross-section, and each maximum width is defined along a direction perpendicular to the longitudinal axis of the device.

[0025] These features enable the inlet flow path to, on the one hand, adapt a part of the inlet flow path, namely the flow path outlet cross-section, to a flat-shaped heating chamber and, on the other hand, select another shape for the flow path inlet cross-section. Furthermore, these features enable the manufacture of the inlet flow path to be facilitated, for example especially when the inlet flow path exhibits very small dimensions.

[0026] According to some embodiments, the flow path inlet cross-section exhibits a shape different from a rectangular shape. For example, the flow path inlet cross-section may exhibit a circular shape or an elliptical shape.

[0027] These features enable a transition in shape between the flow path inlet cross-section and the flow path outlet cross-section. This enables the inlet flow path to be manufactured in a particularly easy manner.

[0028] For example, the inlet flow path may be integrated with the shape of the flow path outlet cross-section from the shape of the flow path inlet cross-section so as to exhibit a rectangular flow path outlet cross-section.

[0029] According to some examples, the area of ​​each cross-section of the inlet channel can be constant. In addition, for example, the maximum width of the channel inlet cross-section may be smaller than the maximum width of the channel outlet cross-section. "Cross-sectional area" is understood to be the size of the channel in, for example, in square millimeters, depending on the cross-section. In this case, the inlet channel may exhibit a transition or integration from the circular or elliptical shape of the channel inlet cross-section to the rectangular shape of the channel outlet cross-section by maintaining the same area in each cross-section of the inlet channel. This makes it possible to obtain inlet channel cross-sections of different shapes between the channel inlet cross-section and the channel outlet cross-section.

[0030] According to some examples, for instance, the area of ​​a circular channel inlet cross-section may be smaller than the area of ​​a rectangular channel outlet cross-section. This can increase the pressure loss of the airflow, particularly adjacent to the channel inlet cross-section. Furthermore, this makes it possible to manufacture inlet channels in an easy manner. In fact, despite the small area of ​​the channel inlet cross-section, the diameter of a circular channel inlet cross-section may be larger than the minimum diameter of a rectangular cross-section having the same area. In some cases, it may be difficult to machine a channel to have a very small channel diameter, such as less than 1.2 mm, and these characteristics may allow the use of a larger diameter channel, which may still result in a high pressure loss of the airflow. "Pressure loss" is understood, in particular, to be the difference between the air pressure inside the inlet channel and the air pressure outside the inlet channel (i.e., the air before it flows into the inlet channel).

[0031] According to some embodiments, each of the multiple cross-sections is substantially rectangular.

[0032] These features result in a simple inlet channel structure. In addition, for example, the inlet channel matches the shape of the heating chamber, which has a flat shape that allows for efficient aerosol generation.

[0033] According to some embodiments, a single inlet channel exhibits a rounded transition with respect to the outer surface of the distal wall of the device housing.

[0034] These features enhance the Coanda effect of the airflow entering the inlet channel. In particular, when air from the outside is drawn into the inlet channel, the rounded transition area from the outer surface to the inside of the inlet channel causes the airflow or jet to adhere to the inner surface of the inlet channel.

[0035] According to some embodiments, the distance between the distal wall of the device housing and the distal end of a flat heating chamber, along the longitudinal axis of the device, defines the flow path length, which is longer than the heating chamber length, corresponding to the distance between the proximal and distal ends along the longitudinal axis of the device.

[0036] These characteristics result in the inlet channel exhibiting a large length, also called the channel length, such as a length greater than 10 mm, preferably greater than 15 mm, or even greater than 17 mm or 20 mm. Thus, the inlet channel is adapted to supply a laminar or nearly turbulent airflow to a flat-shaped heating chamber. This improves aerosol extraction.

[0037] According to some embodiments, the area defined by at least one cross-section perfectly coincides with and / or completely covers the area defined by the cross-section of the cigarette.

[0038] These features further improve airflow. In particular, when the cross-section matches the area defined by the tobacco cross-section, a smooth transition of airflow from the inlet channel to the tobacco cross-section is achieved.

[0039] For example, at least one cross-section of the inlet channel adjacent to the tobacco cross-section may have the same shape as the tobacco article, for example, 17 mm × 11.5 mm × 1.2 mm. This at least one cross-section is in particular the channel outlet cross-section.

[0040] According to some embodiments, at least one outer surface of a tobacco article extending along its axis exhibits a plurality of grooves that form air passages.

[0041] These features allow the tobacco article to be very compact while simultaneously exhibiting a large surface area for aerosol extraction. In particular, the grooves allow for an increased surface area adapted to contact the airflow during heating in the heating chamber.

[0042] The present invention further relates to an assembly comprising the aerosol generating device described above, further comprising a flat tobacco article having a tobacco portion that is received in a flat heating chamber.

[0043] The present invention and its advantages are given as non-limiting examples and will be better understood by reading the following description, which is made with reference to the accompanying drawings. [Brief explanation of the drawing]

[0044] [Figure 1] This is a schematic perspective view of an aerosol generating assembly, which includes an aerosol generating device according to the present invention and a tobacco article that can be used with the aerosol generating device. [Figure 2] Figure 1 is a perspective view of a tobacco product. [Figure 3] Figure 1 is a schematic cross-sectional view of the aerosol generation assembly by a first plane, where the first plane includes the longitudinal axis of the aerosol generation device, and the aerosol generation assembly is according to a first embodiment. [Figure 4] Figure 3 is a schematic cross-sectional view of the aerosol generation assembly, including the longitudinal axis of the device, with respect to a second plane perpendicular to the first plane. [Figure 5] Figure 3 is a schematic rear view of the aerosol generation assembly, oriented along the longitudinal axis of the device, showing the outer surface of the aerosol generation device extending perpendicular to the longitudinal axis of the device. [Figure 6] This is a schematic cross-sectional view of an aerosol generating assembly according to a second embodiment, similar to the figure in Figure 3. [Figure 7] This is a schematic cross-sectional view of an aerosol generating assembly according to a second embodiment, similar to the figure in Figure 4. [Figure 8] This is a schematic cross-sectional view of an aerosol generating assembly according to a second embodiment, similar to the figure in Figure 5. [Figure 9] This is a cross-sectional view of the cigarette article in Figure 1 inserted into the heating chamber of an aerosol generating device, showing the region of airflow enhanced according to the Coanda effect. [Modes for carrying out the invention]

[0045] Before describing the present invention, it should be understood that the present invention is not limited to the structural details described below. It will be apparent to those skilled in the art who benefit from this disclosure that other embodiments are possible and that the invention can be implemented or carried out in various ways.

[0046] As used herein, the term “section” may be defined as a section extending in a plane perpendicular to the longitudinal axis of the device or the axis of the article. For example, if the section relates to a part of an aerosol generating device, such a section extends in a plane perpendicular to the longitudinal axis of the device. Preferably, all sections may extend parallel to one another. For example, each of several sections of a single inlet channel, including a channel inlet section and a channel outlet section, may extend parallel to one another, and in particular perpendicular to the longitudinal axis of the device. For example, a cigarette section forms the section of a cigarette article, and this section extends in a plane perpendicular to the axis of the article. If the axis of the article extends parallel to and is identical to the longitudinal axis of the device, the cigarette section or each cigarette section may extend parallel to each of several sections of a single inlet channel, particularly when inserting a cigarette article into an aerosol generating device.

[0047] The expression "substantially equal" is understood below to mean equal by ±10%, preferably ±5%, and more preferably ±1%. In some examples, this expression may mean exactly equal. For example, "substantially rectangular" or "substantially rectangular shape" is understood to mean that adjacent edges of the rectangular shape may form an angle between them that is substantially equal to 90°, i.e., an angle that deviates from 90° by, for example, ±10%, preferably ±5%, and more preferably ±1%. In some examples, "substantially rectangular" or "substantially rectangular shape" is understood to mean "rectangle" or "rectangular shape".

[0048] Therefore, if at least one reference cross-section among the multiple cross-sections of the first element is substantially rectangular and has a shape substantially equal to the cross-section of the second element, then it is clear, firstly, that both the reference cross-section and the cross-section of the second element are substantially rectangular, and secondly, that the characteristic dimensions of the reference cross-section, including the side lengths and / or angles between two adjacent sides, and the corresponding characteristic dimensions of the cross-section of the second element are equal within the scope of the meaning of the preceding paragraph.

[0049] In other words, determining whether two shapes are substantially equal involves taking into account both the type of shape (e.g., rectangle, triangle, etc.) and the characteristic dimensions of the shape.

[0050] If the reference cross-section has a shape substantially equal to the cross-section of the second element, the reference cross-section is approximately coincident with the cross-section of the second element. If they are exactly equal, the reference cross-section is exactly coincident with the cross-section of the second element.

[0051] As used herein, the terms “aerosol generating device” or “device” may include a vaping device for delivering an aerosol containing an aerosol for vaping to a user using a heater element, which is described in more detail below. The device may be portable. “Portable” may mean a device used when held by a user. The device may be adapted to generate a variable amount of aerosol (as opposed to a fixed amount of aerosol) by, for example, activating a heater element over a variable amount of time. The variable amount of aerosol may be controlled by a trigger. The trigger may be user-activated, such as a vaping button and / or an inhalation sensor. The inhalation sensor may be highly sensitive to inhalation intensity and duration and may allow for the delivery of a variable amount of vapor (to mimic the smoking effect of conventional combustion-type smoking articles such as cigarettes, cigars, or pipes). The device may include a temperature control unit for driving the temperature of the heater and / or heated aerosol generating material (aerosol precursor) to a specific target temperature and then maintaining that temperature at the target temperature to enable efficient aerosol generation.

[0052] As used herein, the term “aerosol” may include suspended matter of vaporizable materials as one or more solid particles, droplets, or gases. Such suspended matter may be present in gases, including air. In general, aerosols as used herein may refer to / include vapors. Aerosols may include one or more components of vaporizable materials.

[0053] As used herein, the terms “vaporizable material” or “precursor,” which may include, for example, nicotine or tobacco and an aerosol-forming agent, may refer to a smokeable material. Tobacco can take the form of various materials such as shredded tobacco, granular tobacco, tobacco leaves, and / or reconstituted tobacco. Suitable aerosol-forming agents include polyols (such as sorbitol, glycerol, and glycols such as propylene glycol or triethylene glycol) and non-polyols (such as monohydric alcohols, acids such as lactic acid, glycerol derivatives, triacetin, triethylene glycol diacetate, esters such as triethyl citrate, glycerin, or vegetable glycerin). In some embodiments, the aerosol-generating agent may be glycerol, propylene glycol, or a mixture of glycerol and propylene glycol. The substrate may also contain at least one of a gelling agent, a binder, a stabilizer, and a humectant.

[0054] First Embodiment Referring to Figures 1 to 5, the aerosol generating assembly 10 according to the first embodiment includes an aerosol generating device 11 and a flat-shaped aerosol generating article 12, also called a flat-shaped cigarette article 12. The aerosol generating device 11 is intended to work together with the flat-shaped cigarette article 12, which is shown in more detail in Figure 2. The flat-shaped cigarette article 12 will be referred to as cigarette article 12 below.

[0055] Referring to Figure 2, the tobacco article 12 exhibits a flat rectangular parallelepiped shape, for example, extending along the article axis X1 and having external dimensions L × W × D. In a typical example, the length L of the article 12 along the article axis X1 is substantially equal to 32 mm, while the width W and depth D of the article 12 are substantially equal to 11.5 mm and 1.2 mm, respectively. According to a different example, the values ​​L, W, and D may be selected within, for example, a range of ±40%. The depth D of the tobacco article 12 is formed by a pair of parallel walls 13A, 13B, hereafter referred to as narrow walls 13A, 13B, and the width W of the tobacco article 12 is formed by a pair of parallel walls 14A, 14B, hereafter referred to as wide walls 14A, 14B. In some embodiments, the edges between the wide walls 14A, 14B and the narrow walls 13A, 13B may be rounded. According to other embodiments of the present disclosure, the tobacco article 12 may have any other suitable flat shape and / or external dimensions.

[0056] The tobacco article 12 includes, for example, a tobacco portion 15 and a mouthpiece portion 16 positioned along the article axis X1. The tobacco portion 15 may be, for example, slightly longer than the mouthpiece portion 16. For example, the length L2 of the tobacco portion 15 along the article axis X1 may be substantially equal to 17 mm. The width W2 of the tobacco portion 15 is substantially equal to the width W of the tobacco article 12. The length L3 of the mouthpiece portion 16 along the article axis X1 may be substantially equal to 15 mm. As in the above case, the values ​​L2 and L3 may be selected within, for example, a range of ±40%. The tobacco portion 15 defines the contact end 18 of the article 12, and the mouthpiece portion 16 defines the mouth end 20 of the article 12. The tobacco portion 15 and the mouthpiece portion 16 may be secured to each other by a wrapper 21 extending around the article axis X1. The wrapper 21 forms the narrow walls 13A, 13B and the wide walls 14A, 14B of the tobacco article 12. In some embodiments, the wrapper 21 is formed from the same packaging sheet. In some other embodiments, the wrapper 21 is formed from separate packaging sheets that separately package portions 15, 16 and are fastened to each other by any other suitable means. The wrapper 21 may include, for example, paper and / or nonwoven fabric and / or aluminum foil. The wrapper 21 may be porous or air-impermeable and form a plurality of air channels extending between the abutment end 18 and the mouth end 20 inside the article 12.

[0057] The mouthpiece portion 16 may include, for example, a core 27 intended to function as a cooler to slightly cool the vapor before the user inhales it. For this purpose, the core 27 may include, for example, corrugated cardboard. The core 27 may be formed into a stable shape through an extrusion and / or rolling process. Advantageously, the core 27 is positioned inside the mouthpiece portion 16 so as to be in full contact with the inner surface of the wrapper 21 that defines the boundary of the mouthpiece portion 16. Additionally or alternatively, the core 27 functions as a filter.

[0058] The tobacco portion 15 contains a vaporizable material and is intended to be heated by the heating chamber, as will be described in more detail below.

[0059] In some examples, the tobacco article 12 consists of a tobacco portion 15. In particular, the tobacco article 12 may lack a mouthpiece portion.

[0060] For example, referring to Figure 9, at least one outer surface of a tobacco article 12 extending along the article axis X1 may have a plurality of grooves 28 that form air passages. The grooves 28 may form embossed air passages that extend parallel to the article axis X1. The grooves 28 may be formed on both sides of, for example, a tobacco portion 15 and may have a constant width and / or depth, for example, along the article axis X1. Each groove 28 may have a width and / or depth that is, in particular, one or more dimensions greater than the average diameter of the tobacco article of the tobacco portion 15, and each tobacco article may be made of, for example, shredded tobacco, granular tobacco, tobacco leaves and / or reconstituted tobacco.

[0061] In this case, the groove 28 is not considered when determining the dimensions and shape of at least one of the multiple cross-sections of a single inlet channel 56, which is substantially rectangular and substantially equal in shape to the tobacco cross-section of the tobacco portion 15 adjacent to the at least one cross-section. In other words, substantially equal is valued by comparison with the tobacco cross-section of the reference tobacco portion, which allows the grooved tobacco portion 15 to be formed by cutting the groove 28 into the outer surface of at least one of the reference tobacco portions.

[0062] Referring again to Figure 1, the aerosol generating device 11 includes a device body 30 extending along the longitudinal axis Y of the device. The device body 30 includes a mouthpiece 32 and a device housing 34, hereafter referred to as the housing 34, which are arranged in a continuous manner along the longitudinal axis Y of the device. According to the example in Figure 1, the mouthpiece 32 and the housing 34 form two distinct parts. In detail, according to this example, the mouthpiece 32 is designed to be fixed to or received into an insertion opening formed in one of the ends of the housing 34. In this case, the tobacco article 12 can be inserted into the device 11 when the mouthpiece 32 is removed from the housing 34. According to another example (not shown), the mouthpiece 32 and the housing 34 form one single part. In this case, the tobacco article 12 can be inserted into the device 11, for example, through an outlet. According to both examples, the mouthpiece 32 defines a through-hole adapted to at least partially receive the tobacco article 12. In detail, the through-hole may be adapted to at least partially receive the mouthpiece portion 16 of the tobacco article 12. According to yet another embodiment (not shown), the aerosol generating device 11 is not provided with a mouthpiece 32. In this case, the mouthpiece portion 16 of the tobacco article 12 may form a mouth-side end designed to come into contact with the user's lips and / or mouth during a vaping session.

[0063] The aerosol generating device 11 further includes a flat heating chamber 38 extending along the device's longitudinal axis Y between a proximal end 40 configured to receive at least a tobacco portion 15 of a flat tobacco article 12 and a distal end 42 opposite to the proximal end 40. The flat heating chamber 38 is formed particularly inside the housing 34. When the tobacco portion 15 is received in the heating chamber 38, the article axis X1 may extend parallel or may be identical to the device's longitudinal axis Y. The proximal end 40 may open, for example, to a through-hole in the mouthpiece 32. The distal end 42 opens to a single inlet channel 56, which will be described in more detail below.

[0064] The heating chamber 38 may include heating zones adapted to heat the tobacco portion 15 of the tobacco article 12 when the tobacco article 12 is received into the heating chamber 38, particularly through the through-hole of the mouthpiece 32 and the proximal end 40 of the heating chamber 38.

[0065] The heating chamber 38 has a flat shape. More specifically, as a tobacco article 12, the heating chamber 38 may also form a rectangular parallelepiped shape extending along the longitudinal axis Y of the device. For example, the heating chamber 38 may include a pair of parallel narrow walls extending along the longitudinal axis Y of the device and a pair of parallel broad walls similarly extending along the longitudinal axis Y of the device, connecting the proximal end 40 to the distal end 42. The heating chamber 38 is configured in particular to receive a tobacco article 12 such that the corresponding broad walls 14A, 14B of the tobacco article 12 face the corresponding broad walls of the heating chamber 38, the corresponding narrow walls 13A, 13B of the tobacco article 12 face the corresponding narrow walls of the heating chamber 38, and the contact end 18 of the tobacco article 12 faces the distal end 42.

[0066] The housing 34 defines the boundaries of the internal space of the device 11, which accommodates various elements designed to perform different functions of the device 11. This internal space can accommodate, for example, a battery 36 for supplying power to the device 11, a flat heating chamber 38, a heater element 39 for heating the heating chamber 38, a tobacco article 12 to be received in the heating chamber 38, and a controller (not shown) for controlling the operation of the heating element 39.

[0067] The housing 34 may, for example, be a rectangular parallelepiped with a flat shape extending along the longitudinal axis Y of the device. Referring to Figure 1, the housing 34 may include a pair of parallel narrow walls 44A, 44B and a pair of parallel wide walls 46A, 46B connecting the edges of the narrow walls 44A, 44B. The narrow walls 44A, 44B and the wide walls 46A, 46B extend in particular parallel to the longitudinal axis Y of the device. The housing 34 may further include a front end 48 configured to receive the mouthpiece 32 and a distal wall 50. The distal wall 50 extends perpendicular to the longitudinal axis Y of the device and may have an outer surface 52. In particular, the distal wall 50 may form the rear end of the device 11 opposite to the front end 48. In some embodiments, the edges between the wide walls 46A, 46B and the narrow walls 44A, 44B may be rounded. In some embodiments, the edges between these walls 44A, 44B, 46A, 46B and the distal wall 50 and / or front end 48 can be rounded.

[0068] For example, referring to Figures 3 and 4, the aerosol generating device 11 further includes a rear portion 54 extending between the distal end 42 of the flat heating chamber 38 and the distal wall 50 of the housing 34.

[0069] The rear portion 54 defines a single air passage 56 configured to provide airflow into the heating chamber 38. The single inlet passage 56 extends along the device longitudinal axis Y and has multiple cross-sections perpendicular to the device longitudinal axis Y. At least one of the multiple cross-sections is substantially rectangular. The at least one cross-section has a shape substantially equal, preferably exactly equal, to the tobacco cross-section of the tobacco portion 15 adjacent to this at least one cross-section. Thus, the tobacco cross-section may be located particularly adjacent to the single inlet passage 56 and / or form the distal end of the tobacco portion 15.

[0070] In particular, a single inlet channel 56 may be bounded along the longitudinal axis Y of the device by a channel inlet cross section and a channel outlet cross section that define the air inlet. The channel inlet cross section may extend along the distal wall 50, and in particular may extend in the same plane as the outer surface 52 of the distal wall 50. The channel outlet cross section may define the boundary of the single inlet channel 56 at the end opposite to the channel inlet cross section. In particular, the channel outlet cross section may be adjacent to the heating chamber 38. The channel outlet cross section of the single inlet channel 56 may have a substantially rectangular shape. Preferably, the area defined by the channel outlet cross section may be exactly the same as or completely cover the area defined by the cigarette cross section. Preferably, according to the first embodiment, as shown, for example, in Figures 3 to 5, each of the multiple cross sections of the single inlet channel 56, including the channel inlet cross section and the channel outlet cross section, may be substantially rectangular. For example, each cross section may have the same area.

[0071] A single inlet channel 56 may be bounded by at least one inner surface 58 connecting the channel inlet cross section to the channel outlet cross section, in a direction perpendicular to the device longitudinal axis Y. For example, in the case of a rectangular cross section of a single inlet channel 56, the inner surface 58 may be formed by four inner walls. Preferably, the inner surface 58 may form an angle of less than 90° with the device longitudinal axis Y at each point. For example, the inner surface 58 may extend parallel to the device longitudinal axis Y, i.e., form an angle equal to 0° with axis Y. For example, the inner surface 58 may exhibit a smooth transition between the channel inlet cross section and the channel outlet cross section. In other words, for example, the inner surface 58 may have no steps.

[0072] For example, a single inlet channel 56 may have a rounded transition portion with the outer surface 52 of the distal wall 50 (not shown). In particular, the outer surface 52 may become integrated with the inner surface 58 via a curved or rounded transition portion.

[0073] For example, a single inlet channel 56 has a length greater than the length of the heating chamber 38 along the longitudinal axis Y of the device. For instance, the distance between the distal wall 50 of the device housing 34 and the distal end 42 of the flat heating chamber 38, along the longitudinal axis Y of the device, defines the channel length. The channel length is equal to the length of the rear portion 54 in particular. The channel length may be longer than the heating chamber length, which corresponds to the distance between the proximal end 40 and the distal end 42 along the longitudinal axis Y of the device.

[0074] Figure 9 shows an example of region A in the heating chamber 38 where the airflow is enhanced according to the Coanda effect, which is achieved by the shape of the single inlet channel 56. In particular, when the device 11 is in operation, the airflow in the flat heating chamber 38 adheres to the wall of the heating chamber 38 due to the shape and / or length of the single inlet channel 56.

[0075] Second Embodiment A second embodiment of the aerosol generating assembly 10 will now be described with reference to Figures 6 to 8. The aerosol generating assembly 10 according to the second embodiment includes at least some, preferably all, of the features of the first embodiment, except for the differences described below. The same or corresponding elements will not be described again. The same or corresponding elements will be given the same reference numerals. For example, the tobacco article 12 in the second embodiment may be identical to that in the first embodiment.

[0076] In contrast to the first embodiment, the channel inlet cross-section may have a shape other than rectangular, such as a circular or elliptical shape. For example, a circular channel inlet cross-section is shown in Figure 8, which is a rear view of the aerosol generating device 11, i.e., a view along the device's longitudinal axis Y. According to some examples, a single inlet channel 56 transitions gradually from a channel inlet cross-section shape, such as a circular shape, to a channel outlet cross-section shape, such as a rectangular shape, or becomes integrated with it. For example, the inner surface 58 connecting the channel inlet cross-section to the channel outlet cross-section may form an angle of less than 90° with the device's longitudinal axis Y at each point. For example, the inner surface 58 may have a smooth transition between the channel inlet cross-section and the channel outlet cross-section.

[0077] In particular, the inner surface 58 may define at least one straight line 60, for example four straight lines 60, that connect the corresponding edges of the substantially rectangular shape of the flow outlet cross-section to the flow inlet cross-section. Such straight lines 60 of the inner surface 58 are shown, for example, in Figure 7.

[0078] Preferably, the maximum width of a single inlet channel 56 in the channel inlet cross-section, such as the radius in the case of a circular cross-section, is smaller than the maximum width of a single inlet channel 56 in the channel outlet cross-section, such as the transverse width of the channel outlet cross-section in the case of a rectangular cross-section. Each maximum width is defined along a direction perpendicular to the longitudinal axis Y of the device.

[0079] For example, any feature of the housing 34 according to the first embodiment can be combined with a single inlet channel 56 according to the second embodiment.

Claims

1. An aerosol generating device (11) comprising a flat heating chamber (38) extending along the longitudinal axis (Y) of the device between a proximal end (40) configured to operate with a flat tobacco article (12) and to receive at least the tobacco portion (15) of the flat tobacco article (12) and a distal end (42) opposite to the proximal end (40), The rear portion (54) includes the distal end (42) of the flat heating chamber (38) and the distal wall (50) of the device housing (34), the rear portion (54) defines a single inlet channel (56) configured to provide airflow into the heating chamber (38), The aerosol generating device (11) has a single inlet channel (56) that extends along the longitudinal axis (Y) of the device and has a plurality of cross-sections perpendicular to the longitudinal axis (Y) of the device, wherein at least one of the plurality of cross-sections is substantially rectangular and has a shape substantially equal to the cross-section of the tobacco portion (15) adjacent to the at least one cross-section.

2. The aerosol generating device (11) according to claim 1, wherein the single inlet channel (56) is bounded along the longitudinal axis (Y) of the device by a channel inlet cross section defining an air inlet and a channel outlet cross section adjacent to the heating chamber (38), and the channel outlet cross section has a substantially rectangular shape.

3. The aerosol generating device (11) according to claim 2, wherein the single inlet channel (56) is bounded by at least one inner surface (58) in a direction perpendicular to the longitudinal axis (Y) of the device, the inner surface (58) connects the channel inlet cross section to the channel outlet cross section, and the inner surface (58) forms an angle of less than 90° with the longitudinal axis (Y) of the device at each point.

4. The aerosol generating device (11) according to claim 3, wherein the inner surface (58) exhibits a smooth transition between the channel inlet cross section and the channel outlet cross section.

5. The aerosol generating device (11) according to claim 3 or 4, wherein the at least one inner surface (58) defines at least one straight line (60) connecting the substantially rectangular edge of the channel outlet cross section to the channel inlet cross section.

6. The aerosol generating device (11) according to any one of claims 2 to 5, wherein the maximum width of the single inlet channel (56) in the channel inlet cross section is smaller than the maximum width of the single inlet channel (56) in the channel outlet cross section, and each maximum width is defined along a direction perpendicular to the longitudinal axis (Y) of the device.

7. The aerosol generating device (11) according to any one of claims 2 to 6, wherein the cross-section of the channel inlet has a shape different from that of a rectangle.

8. The aerosol generating device (11) according to claim 7, wherein the cross-section of the channel inlet has a circular or elliptical shape.

9. The aerosol generating device (11) according to any one of claims 1 to 6, wherein each of the plurality of cross-sections is substantially rectangular.

10. The aerosol generating device (11) according to any one of claims 1 to 9, wherein the single inlet channel (56) exhibits a rounded transition portion with the outer surface (52) of the distal wall (50) of the device housing (34).

11. The aerosol generating device (11) according to any one of claims 1 to 10, wherein the distance between the distal wall (50) of the device housing (34) and the distal end (42) of the flat heating chamber (38), along the longitudinal axis (Y) of the device, defines the flow path length, and the flow path length is longer than the heating chamber length corresponding to the distance between the proximal end (40) and the distal end (42) along the longitudinal axis (Y) of the device.

12. The aerosol generating device (11) according to any one of claims 1 to 11, wherein the area defined by the at least one cross-section completely coincides with and / or completely covers the area defined by the tobacco cross-section.

13. The aerosol generating device (11) according to any one of claims 1 to 12, wherein at least one outer surface of the tobacco article (12) extending along the article axis has a plurality of grooves (28) that form an air passage.

14. An aerosol generating assembly (10) comprising an aerosol generating device (11) according to any one of claims 1 to 13, further comprising a flat tobacco article (12) having the tobacco portion (15) that is received in the flat heating chamber (38).

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