WO2024018010A1

WO2024018010A1 - Heating system for an aerosol generating assembly

Info

Publication number: WO2024018010A1
Application number: PCT/EP2023/070174
Authority: WO
Inventors: Tilen CEGLAR; Jaakko MCEVOY
Original assignee: Jt International Sa
Priority date: 2022-07-22
Filing date: 2023-07-20
Publication date: 2024-01-25

Abstract

A heating system (50) for an aerosol generating assembly, the heating system comprising: a wick (18), having an absorbing surface (23) designed to be in contact with a liquid vaporizable material; vapor channels (21); a heater (20), for heating the wick (18) so that the liquid vaporizable material absorbed by the wick forms aerosol within the vapor channels; guiding channels (19), fluidly connected to the vapor channels so that airflows (42) coming from the guiding channels (19) flows through the vapor channels (21) for carrying the aerosol to a vapor outlet of the aerosol generating assembly; and a redistribution chamber (22), the guiding channels (19) being fluidly connected to the vapor channels (21) via the redistribution chamber (22), so that the airflows (42) coming from the guiding channels (19) mixes in the redistribution chamber (22) before entering the vapor channels (21).

Description

Heating system for an aerosol generating assembly

FIELD OF THE INVENTION

The present invention concerns a heating system for an aerosol generating assembly and an aerosol generating assembly comprising a heating system.

BACKGROUND OF THE INVENTION

Different types of aerosol generating systems are known in the art. Generally, such systems comprise a storage compartment for storing a liquid aerosol forming precursor. A heating system is formed of one or more electrically activated resistive heating elements arranged to heat said precursor to generate the aerosol. A wick in fluid communication with the storage compartment provides the liquid aerosol forming precursor to the heating system. When the wick is heated, the aerosol is released from the wick into a flow path extending between an inlet and an outlet of the device. The outlet may be arranged as a mouthpiece, through which a user inhales the aerosol.

It is known that vapor channels are formed at the wick, for the aerosol to be released in the vapor channels. During a puff, the airflow incoming from the inlet flows through the vapor channels, thereby carrying the released aerosol to the outlet.

However, some of the known aerosol generating systems experience unequal distribution of the airflows in the vapor channels, resulting in poor efficiency of the aerosol release, saturation and/or overheating of some of the vapor channels, as the aerosol is not equally carried away by the airflow in these vapor channels compared to the others.

SUMMARY OF THE INVENTION

One of the aims of the present invention is to provide a heating system which solves the above-mentioned issues. Particularly, a heating system according to the invention aims to improve the distribution of an incoming airflow into the vapor channels.

For this purpose, the invention concerns a heating system for an aerosol generating assembly, the heating system comprising: - a wick, having an absorbing surface designed to be in contact with a liquid vaporizable material;

- vapor channels;

- a heater, for heating the wick so that the liquid vaporizable material absorbed by the wick forms aerosol within the vapor channels; wherein the vapor channels are interposed between the heater and the wick, wherein the vapor channels are formed by the wick itself or by an interface separate from the wick, said interface being interposed between the heater and the wick;

- guiding channels, fluidly connected to the vapor channels so that airflows coming from the guiding channels flows through the vapor channels for carrying the aerosol to a vapor outlet of the aerosol generating assembly; and

- a redistribution chamber, the guiding channels being fluidly connected to the vapor channels via the redistribution chamber, so that the airflows coming from the guiding channels mixes in the redistribution chamber before entering the vapor channels.

By implementing these features, the heating system according to the invention ensures that the incoming airflow is brushed and oriented by the guiding channels and then at least partially mixed in the redistribution chamber. This enables a partial redistribution of the incoming airflow in the redistribution chamber, so that the airflow may be more evenly distributed to the vapor channels. Thus, the aerosol generated in each vapor channel may be more equally evacuated towards the vapor outlet, thereby promoting better efficiency of the aerosol generation within all the vapor channels. Thanks to these features, overheating and saturation of the vapor channels may be prevented.

According to some embodiments, every guiding channel and every vapor channel open in the redistribution chamber. In other words, no other element than the redistribution chamber connects the guiding channels to the vapor channels. In other words, the distribution chamber is delimited by a respective outlet of the guiding channels and by a respective inlet of the vapor channels.

According to some embodiments, the redistribution chamber defines several individual redistribution zones, and each redistribution zone connects two or more of the guiding channels to a single of the vapor channels, said two or more guiding channels and single vapor channel opening in the redistribution zone. By implementing these features, the airflows coming from the two or more guiding channels are mixed in the individual redistribution zone of the redistribution chamber before entering the single vapor channel. Thus, efficient distribution of the airflow rate in the vapor channels may be obtained.

According to some embodiments, some or each of the guiding channels are open offset relative to the vapor channels.

By implementing these features, the airflows coming from the guiding channels are forced to change direction before entering into the vapor channel, thereby promoting mixing of said airflows.

According to some embodiments the number of the guiding channels is equal to or greater than the number of the vapor channels, preferably at least twice of the number of the vapor channels.

By implementing these features, the guiding channels enables dividing an incoming airflow into a relatively high number of guided airflows, which may efficiently mix and be redistributed in the redistribution chamber before entering the vapor channels.

According to some embodiments, the total cross-sectional area of the guiding channels is substantially equal to the total cross-sectional area of the vapor channels.

By implementing these features, the guiding channels deliver the airflows to the redistribution chamber at a flow speed similar to the flow speed in the vapor channels.

According to some embodiments, each guiding channel has a respective cross- sectional area substantially equal to the respective cross-sectional areas of the other guiding channels.

By implementing these features, a regular flow speed of the airflows in the guiding channels may be enabled.

According to some embodiments, the guiding channels are homogeneously distributed. By implementing these features, a uniform airflow rate throughout the airflow cross section in the redistribution chamber may be obtained.

According to some embodiments, at least one bypass channel, separate from the vapor channels, is defined along the wick and opens in the redistribution chamber for connecting the redistribution chamber to the vapor outlet and wherein a cross-sectional area of the or each bypass channel is less than the respective cross-sectional areas of each vapor channel.

By implementing these features, a bypass airflow flowing through the or each bypass channel may be reduced to a minimum, and flowing through the vapor channels may be increased.

According to some embodiments, the vapor channels are formed by the wick itself.

By implementing these features, the wick itself forms the vapor channels, so as to reduce the amount of parts necessary to manufacture the heating system. In other embodiments, the vapor channels may be formed by an interface, i.e. a part separate from the wick, interposed between the heater and the wick. The interface may promote heat transmission from the heater to the wick.

According to some embodiments, the vapor channels are arranged along the wick, opposite to the absorbing surface of the wick.

By implementing these features, the vapor channels where the aerosol needs to be formed receive are more exposed to the heat generated by the heater than the absorbing surface, not intended to form aerosol. Thus, formation of aerosol is made more efficient and localized in the vapor channels.

In some embodiments, the guiding channels are distributed along a first transversal direction of the heating system. In some embodiments, the vapor channels are distributed along the first transversal direction.

In some embodiments, each guiding channel and vapor channel is oriented parallel to a second transversal direction of the heating system, preferably perpendicular to the first transversal direction. In some embodiments, the vapor channels are positioned in the second transversal direction relative to the guiding channels.

In some embodiments, each guiding channel defines a guiding length parallel to the second transversal direction and each vapor channel defines a vapor length along the second transversal direction, each guiding length being smaller than each of the vapor lengths.

In some embodiments, for each vapor channel, a redistribution length of the redistribution chamber is smaller than the vapor length of said vapor channel, the redistribution length being measured parallel to the second transversal direction, between said vapor channel and the closest of the guiding channels.

The invention also concerns an aerosol generating assembly comprising the heating system as defined above.

According to some embodiments, the aerosol generating comprises:

- an aerosol generating device; and

- a cartridge, storing the liquid vaporizable material, the cartridge being configured to be engaged with the aerosol generating device; the heating system being integrated partially in the aerosol generating device and partially in the cartridge so that the liquid vaporizable material is in contact with the absorbing surface when the cartridge is engaged.

According to some embodiments, the aerosol generating assembly further comprises an airflow inlet, the guiding channels fluidly connecting the airflow inlet to the redistribution chamber. According to some embodiments, the airflow inlet is formed of a single inlet channel, or of a number of inlet channels smaller than the number of guiding channels and than the number of vapor channels, and no other airflow inlet lead to the guiding channels.

According to some embodiments, the aerosol generating assembly further comprises a mouthpiece forming the vapor outlet, the vapor channels fluidly connecting the redistribution chamber to the vapor outlet.

According to some embodiments, the aerosol generating assembly comprises a power supply, preferably including a battery, for powering the heater. BRIEF DESCRIPTION OF THE DRAWINGS

The invention and its advantages will be better understood upon reading the following description, which is given byway of non-limiting example and which is made with reference to the appended drawings, in which:

- Figure 1 is a schematic view of an aerosol generating assembly according to a first embodiment of the invention;

- Figure 2 is a schematic view of a heating system belonging to the aerosol generating assembly of Figure 1 ;

- Figure 3 is a schematic view the heating system of Figure 2;

- Figure 4 is a schematic view similar to Figure 3, of a heating system according to a second embodiment.

DETAILED DESCRIPTION OF THE INVENTION

Before describing the invention, it is to be understood that it is not limited to the details of construction set forth in the following description. It will be apparent to those skilled in the art having the benefit of the present disclosure that the invention is capable of other embodiments and of being practiced or being carried out in various ways.

As used herein, the term “aerosol generating assembly” or “assembly” may include a vaping device to deliver an aerosol to a user, including an aerosol for vaping, by means of aerosol generating unit (e.g. an aerosol generating element which generates vapor which condenses into an aerosol before delivery to an outlet of the device at, for example, a mouthpiece, for inhalation by a user). The device may be portable. “Portable” may refer to the device being for use when held by a user. The device may be adapted to generate a variable amount of aerosol, e.g. by activating a heater system for a variable amount of time (as opposed to a metered dose of aerosol), which can be controlled by a trigger. The trigger may be user activated, such as a vaping button and/or inhalation sensor. The inhalation sensor may be sensitive to the strength of inhalation as well as the duration of inhalation to enable a variable amount of vapor to be provided (so as to mimic the effect of smoking a conventional combustible smoking article such as a cigarette, cigar or pipe, etc.). The device may include a temperature regulation control to drive the temperature of the heater and/or the heated aerosol generating substance (aerosol pre-cursor) to a specified target temperature and thereafter to maintain the temperature at the target temperature that enables efficient generation of aerosol.

As used herein, the term “aerosol” may include a suspension of precursor as one or more of: solid particles; liquid droplets; gas. Said suspension may be in a gas including air. Aerosol herein may generally refer to/include a vapor. Aerosol may include one or more components of the precursor.

As used herein, the term “liquid vaporizable material” or “aerosol forming precursor” or “precursor” or “aerosol forming substance” or “substance” or “vaporizable material” is used to designate any material that is vaporizable in air to form aerosol. Vaporisation is generally obtained by a temperature increase up to the boiling point of the vaporization material, such as at a temperature up to 400°C, preferably up to 350°C. The vaporizable material may, for example, comprise or consist of an aerosol-generating liquid, gel, or wax or the like or an aerosol -generating solid that may be in the form of a rod, which contains processed tobacco material, a crimped sheet or oriented strips or shreds of reconstituted tobacco (RTB), or any combination of these. The vaporizable material may comprise one or more of: nicotine; caffeine or other active components. The active component may be carried with a carrier, which may be a liquid aerosol forming agent. The carrier may include propylene glycol or glycerin or a combination thereof. A flavoring may also be present. The flavoring may include Ethylvanillin (vanilla), menthol, Isoamyl acetate (banana oil) or similar.

DESCRIPTION OF A FIRST EMBODIMENT OF THE INVENTION

Figure 1 shows an aerosol generating assembly 10 according to a first embodiment of the invention comprising a cartridge 14 and an aerosol generating device 12.

The aerosol generating device 12 is configured to operate with the cartridge 14. In particular, the device 12 comprises a body 13 defining a cavity configured to receive the cartridge 14. The cartridge 14 and the aerosol generating device 12 may be detachably engaged in a functioning relationship. Various mechanisms may be used to connect the cartridge 14 and the aerosol generating device 12 that include a threaded engagement, a press-fit engagement, an interference fit, a magnetic engagement, or the like. In a variant, the cartridge 14 may be fixed permanently to the aerosol generating device 12. The aerosol delivery assembly 10 may be substantially rod-like shaped, as shown on Figure 1 .

In reference to Figure 1 , the aerosol generating assembly 10 comprises a storage compartment 16. The storage compartment 16 is arranged in or formed by the cartridge 14. The storage compartment 16 contains a liquid vaporizable material. Once the liquid vaporizable material is exhausted, the cartridge 14 may be replaced by the user with a new cartridge 14. Alternatively, the cartridge 14 and storage compartment 16 are integrated to the assembly 10, the cartridge 14 being permanently engaged with the aerosol generating device 12, and said cartridge 14 can be refilled by the user.

The aerosol generating assembly 10 may comprise a mouthpiece 17, arranged at a first end thereof. The mouthpiece 17 defines at least one channel forming a vapor outlet 15. The mouthpiece 17 may be attached on the distal end of the cartridge 14, may be a part of the cartridge 14, or may be a part of the aerosol generating device 12. In use, a user may draw a flow of vapor, i.e. a flow of air charged with aerosol from the vapor outlet 15 of the mouthpiece 17.

The aerosol generating assembly 10 may comprise an airflow inlet 11 , formed by at least one channel. The airflow inlet 1 1 may be positioned at a second end of the generating assembly 10 as shown in figure 1 , the second end being opposite to the first end. Alternatively, the airflow inlet 11 may be positioned laterally between the first and second ends. In this case, the airflow inlet 1 1 preferably comprises several channels positioned at different locations of the assembly 10, between the first and second ends. The aerosol generating device 12 fluidly connects the airflow inlet 1 1 to the vapor outlet 15, so that when the user draws the flow of vapor from the outlet 15, an airflow is drawn into the aerosol generating assembly 10 at the airflow inlet 1 1 thereof, the airflow flowing through the aerosol generating device 12, the airflow thereby getting loaded with aerosol generated in a heating system for forming vapor, said vapor flowing to the vapor outlet 15 for the user to inhale it.

In reference to Figures 1 and 2, the aerosol generating device 12 defines a longitudinal direction X12, a first transversal direction Y12 and a second transversal direction Z12. Preferably, the first end of the aerosol assembly 10 is positioned in the longitudinal direction X12 relative to the second end. Preferably, the storage compartment 16 is arranged between the first end and the aerosol generating device 12 along direction X12.

The assembly 10 further comprises a heating system 50 which is integrated at least partially in the aerosol generating device 12 and at least partially in the cartridge 14. The heating system 50 comprises a wick 18, vapor channels 21 , a heater 20, guiding channels 19, a redistribution chamber 22, a power supply 24 and a controller 26. In the preferred example, the heater 20, the power supply 24 and the controller 26 are integrated in the aerosol generating device 12 and the other elements of the heating system 50 are integrated in the cartridge 14. In some examples, the cartridge 14 can further include the heater 20.

Preferably, the heater 20, the vapor channels 21 , the wick 18 and the storage compartment 16 are arranged successively in this order along direction X12.

The wick 18 has an absorbing surface 23, oriented towards the storage compartment 16. The absorbing surface 23 of the wick 18 is in contact with the liquid vaporizable material contained therein.

The wick 18 has a heating surface 25, opposite to the absorbing surface 23, turned towards the heater 20. In the preferred example, when the cartridge 14 is engaged with the aerosol generating device 12, the heater 20 is configured to heat the heating surface 25. The absorbing surface 23 is positioned in the direction X12 relative to the heating surface 25.

The wick 18 is a porous element, configured to absorb liquid vaporizable material from the compartment 16, through the absorbing surface 23, so that the wick 18 gets at least partially impregnated with the liquid vaporizable material, up to the heating surface 25. In particular, the wick 18 is configured to regulate the providing of liquid vaporizable material towards the vapor channels 21. For being porous, the wick may comprise flowable solid particles or a porous solid monolithic element, such as porous ceramic.

The vapor channels 21 are formed at the heating surface 25, along the heating surface. The vapor channels 21 may be formed by the wick 18 itself, along the heating surface 25. These vapor channels 21 can for example be formed by grooves defined at the heating surface 25. In this case, an interface made from a heat conducting material can be interposed between the wick 19 and the heater 20. Alternatively, the vapor channels 21 may be formed by an interface part, separate from the wick 18, arranged along the heating surface 25 of the wick 18. Preferably, the vapor channels 21 are distributed over most or all of the heating surface 25.

As best visible in Figure 2, the vapor channels 21 are interposed between the wick 18 and the heater 20, and are preferably in contact with the heater 20 or with an additional interface as explained above. As shown in Figure 3, each vapor channel 21 is parallel to direction Z12. The vapor channels 21 are regularly distributed along direction Y12, i.e. are homogeneously distributed. Here, a total of five vapor channels 21 is provided. However, a different number of vapor channels 21 may be provided, such as between five and thirty vapor channels 21 , preferably fifteen vapor channels 21 .

As best visible in Figure 3, the wick 18 has a rectangular-shaped cross-section, the cross-section being defined perpendicular to the direction X12, or the heating surface 25 is rectangular-shaped.

Each vapor channel 21 has an inlet 31 and an outlet 32, the outlet 32 being arranged in the direction Z12 relative to the inlet 31 . In this embodiment, the inlets 31 are distributed parallel to the direction Y12 and at the same position along direction Z12. In this embodiment, the outlets 32 are distributed parallel to the direction Y12 and at the same position along direction Z12. Preferably, the inlets 31 are arranged at a first straight edge of the rectangular-shaped heating face 25 of the wick 18 and the outlets 32 are arranged at an opposite second straight edge of the rectangular-shaped heating face 25. Each vapor channel 21 defines a respective vapor length L21 , measuring the distance between the inlet 31 and the outlet 32 of this vapor channel 21 parallel to direction Z12. Here, all the vapor lengths L21 are equal to each other.

Each vapor channel 21 preferably has a respective cross-sectional area and/or shape that are(is) equal to the respective cross-sectional areas of the other vapor channels 21 at each cross-section respective to direction Z12. In other words, each vapor channel 21 preferably has the same size and/or shape. Additionally, the cross-sectional area and/or shape of each vapor channel 21 can be constant along direction Z12. In other examples, the vapor channels 21 can define different cross-sectional areas and/or shapes. Additionally or alternatively, at least some vapor channels 21 can define a cross-sectional area and/or shape which vary(ies) along direction Z12. As best visible in Figures 2 and 3, the vapor channels 21 are positioned in the direction Z12 relative to the guiding channels 19. The guiding channels 19 are preferably formed by a part separate from the wick 18, such as by a part of the body 13.

As shown in Figure 3, each guiding channel 19 is parallel to direction Z12. The guiding channels 19 are regularly distributed along direction Y12, i.e. the guiding channels 19 are homogeneously distributed. Here, a total of ten guiding channels 19 is provided. However, a different number of guiding channels 19 may be provided, such as between ten and fifty guiding channels 19, preferably thirty guiding channels 19. The number of the guiding channels 19 is at least equal to the number of vapor channels 21. Preferably, the number of guiding channels 19 is greater than the number of the vapor channels 21 , preferably at least twice of the number of the vapor channels 21 .

Each guiding channel 19 has an inlet 33 and an outlet 34, the outlet 34 being arranged in the direction Z12 relative to the inlet 33. In this embodiment, the inlets 33 are distributed parallel to the direction Y12 and at the same position along direction Z12. In this embodiment, the outlets 34 are distributed parallel to the direction Y12 and at the same position along direction Z12. Each guiding channel 19 defines a respective guiding length L19, measuring the distance between the inlet 33 and the outlet 34 of this guiding channel 19 parallel to direction Z12. Here, all the guiding lengths L19 are equal to each other. Here, all the guiding lengths L19 are shorter than the vapor lengths L21 , such as from five to fifty times shorter than the vapor lengths L21 .

Each guiding channel 19 preferably has a respective cross-sectional area and/or shape that are(is) equal to the respective cross-sectional areas and/or shapes of the other guiding channels 19 at each cross-section respective to direction Z12. In other words, each guiding channel 19 preferably has the same size and/or the same shape. Preferably, the respective cross-sectional areas of the guiding channels 19 are smaller than the respective cross-sectional areas of the vapor channels 21 . Additionally, the cross-sectional area or/and shape of each guiding channel 19 can be constant along direction Z12. In other examples, the guiding channels 19 can define different cross-sectional areas and/or shapes. Additionally or alternatively, at least some guiding channels 19 can define a cross-sectional area and/or shape which vary(ies) along direction Z12. Preferably, the total cross-sectional area of the guiding channels 19 is substantially equal to the total cross-sectional area of the vapor channels 21 . The total cross sectional area of the guiding channels 19 is the sum of the individual cross-section of the guiding channels 19, here measured perpendicular to the direction Z12. The total cross sectional area of the vapor channels 21 is the sum of the individual cross-section of the vapor channels 21 , here measured perpendicular to the direction Z12. Alternatively, the total cross sectional area of the guiding channels 19 may be slightly greater than the total cross sectional area of the vapor channels 21 .

Preferably, the channels 19 and 21 are arranged along a same plane perpendicular to direction X12. Preferably, the outlets 34 face the inlets 31 , at a distance from each other, as shown in Figure 3. Preferably, the channels 19 are offset relative to the channels 21 along the direction Y12. In other words, each outlet 34 is offset relative to the inlets 31 , as shown in figure 3.

The redistribution chamber 22 fluidly connects all the guiding channels 19 to all the vapor channels 21 . Here, the redistribution chamber 22 is positioned between the channels 19 and 21 , in the direction Z12. Every guiding channel 19 opens in the redistribution chamber 22 at their outlet 34. Every vapor channel 21 opens in the redistribution chamber 22 at their inlet 31 . Through the redistribution chamber 22, each outlet 34 is connected to all the inlets 31 and each inlet 31 is connected to all the outlets.

The redistribution chamber 22 defines, for each vapor channel 21 a respective redistribution length L22, measured parallel to the direction Z12, between the outlets 34 of the guiding channels 19 facing the considered vapor channel 21 and the inlet 31 of the vapor channel 21. Preferably, all the lengths L22 are equal, i.e. the space between the channels 19 and 21 is constant. Preferably, the length L22 is smaller than the length L21 and roughly the same size than the length L19, or greater than the length L19.

The airflow inlet 11 is fluidly connected to the vapor outlet 15 through, successively, the guiding channels 19, the chamber 22 and the vapor channels 21. In other words, an airflow drawn into the airflow inlet 11 passes successively through the guiding channels 19, the chamber 22 and the vapor channels 21 before exiting at the vapor outlet 15. In detail, as shown in Figure 3, an airflow 41 drawn at the airflow inlet 1 1 is divided into several airflows 42 by the guiding channels 19, each airflow 42 passing through one of the guiding channels 19. When reaching the redistribution chamber 22, the airflows 42 may mix, at least partially in the redistribution chamber 22. Then, airflows 43, coming from the chamber 22, respectively flow through the vapor channels 21 . Thanks to the mixing of the airflows 42 in the chamber 22 before entering the vapor channels 21 , each airflow 43 is formed of at least two of the airflows 42 coming from the guiding channels 19. This promotes homogeneous distribution of the initial airflow 41 in the vapor channels 21 .

In detail, the redistribution chamber 22 is divided into several individual redistribution zones 46. Only three of the redistribution zones are shown in Figure 3. Preferably, one respective redistribution zone 46 is defined in the redistribution chamber 22 for each vapor channel 21 , at the inlet 31 thereof. Each redistribution zone 46 is connected to the next redistribution zone 46 and is not separated from the other distribution zones by a wall. Each redistribution zone 46 connects two or more of the guiding channels 19 to a single of the vapor channels 21 . The redistribution zones 46 are arranged successively parallel to the direction Y12. Here, each redistribution zone 46 connects the outlets 34 of exactly two guiding channels 19 to the inlet 31 of exactly one vapor channel 21. In other words, exclusively said two outlets 34 and said inlet 31 open in the redistribution zone 46. Thus, the two airflows 42 coming from the channels 19 essentially mix in the corresponding redistribution zone 46 for forming the flow 43, entering the single vapor channel 21 that opens in said redistribution zone 46. Possibly, a small portion of each of the two airflows 42 may escape in the adjacent redistribution zone 46. In any case, the configuration of redistribution chamber 22 and of the channels 19 and 21 force the airflows to become turbulent in the redistribution chamber 22, promoting mixing of the flows 42.

The heater 20 is powered by the power supply 24 to be able to generate heat. The powering of the heater 20 is preferably controlled by the controller 26. The heater 20 is preferably formed of one or more electrically activated resistive heating elements. In a variant, the heater 20 may be an induction heater.

The heater 20 is able to heat the liquid vaporizable material contained in the wick 18 proximate to the heating surface 25, for generating an aerosol made of the liquid vaporizable material within the vapor channels 21 . In practice, the heater 20 is able to heat the wick 18, so that the wick 18 may in turn heat the liquid contained therein. The heater 20 heats the wick 18 through the heating surface 25, i.e. through the channels 21. In an embodiment where the channels 21 are formed by an interface part, the interface part may be formed of a heat conductive material, promoting diffusion of the heat generated by the heater 20 to the wick 18. Under the heat generated by the heater 20, the liquid contained in the wick 18 evaporates into aerosol at the heating surface 25 and is released in the vapor channels 21 . In each vapor channel 21 , the generated aerosol is mixed with the airflow 43, thereby forming a vapor flow 44. The vapor flows 44 exit the vapor channels 21 at the outlet 32 thereof, and regroup into a vapor flow 45, flowing to the vapor outlet 15 for being inhaled by the user. In other words, the airflows 43 carry the aerosol away from the channels 21 towards the vapor outlet 15, thereby forming vapor flows 44 and 45.

DESCRIPTION OF A SECOND EMBODIMENT OF THE INVENTION

Figure 4 shows an alternative embodiment, identical to the embodiment of Figure 3, except for the differences mentioned hereinafter. The features of both embodiments are labelled with the same reference signs.

In the embodiment of Figure 4, the wick 18 has an elliptic-shaped cross-section, the cross-section being defined perpendicular to the direction X12, or the heating surface 25 is rectangular-shaped. In this embodiment of Figure 4, contrary to Figure 3, the inlets 31 are distributed along a first curved edge of the heating surface and the outlets 32 along a second curved edge of the heating surface. Thus, the length L21 of the central vapor channels 21 is greater than the length L21 of the lateral vapor channels 21. The lengths L22 are equal to each other. Thus, the channels 19 are arranged along a curve parallel to the first curved edge.

In the embodiment of Figure 4, two bypass channels 48 are defined along the wick 18, at either side of the wick 18. Each bypass channel 48 is a channel separate from the vapor channels 21 , and is delimited by the wick and the body 13. All the vapor channels 21 are positioned between the two bypass channels 48. Each bypass channel 48 opens in the redistribution chamber 22, at an inlet of the bypass channel 48. The inlet of the bypass channel 48 is next to the inlet 31 of one of the vapor channels 21 . An outlet of the bypass channel 48 is next to the outlet 32 of one of the vapor channels 21 . Each bypass channel 48 connects the redistribution chamber 22 to the vapor outlet 15. A cross-sectional area of each bypass channel 48 is less than the respective cross-sectional areas of each vapor channel 21 . In other words, the vapor channels 21 are larger than the bypass channels 48. The bypass channels 48 enable a bypass airflow, flowing from the chamber 22 to the vapor outlet 15 through the bypass channels 48. While flowing through the bypass channels 48, the by airflow may carry away no aerosol or only few aerosol, as the aerosol is mainly or entirely formed within the vapor channels 21 . In some embodiments, the bypass channels 48 may be provided for mechanical reasons, such as for obtaining a lateral play making the insertion of the wick 18 into the body easier. In this case, the cross-section of the bypass channels 48 may be kept smaller than the vapor channels 21 so that most of the airflows coming from the chamber 22 pass through the vapor channels 21. In other embodiments, the cross-section of the bypass channels 48, while smaller than the individual cross-section of the vapor channels 21 , may enable that the bypass airflow facilitates drawing of vapor at the outlet 15 and/or may enable mixing of the vapor flows 44 with the bypass airflows for forming the vapor flow 45.

OTHER EMBODIMENTS OF THE INVENTION

It will be apparent to those skilled in the art that other embodiments may be carried out in various ways by combining the previous embodiments.

Claims

1 . A heating system (50) for an aerosol generating assembly (10), the heating system (50) comprising:

- a wick (18), having an absorbing surface (23) designed to be in contact with a liquid vaporizable material;

- vapor channels (21);

- a heater (20), for heating the wick (18) so that the liquid vaporizable material absorbed by the wick (18) forms aerosol within the vapor channels (21 ), wherein the vapor channels (21 ) are interposed between the heater (20) and the wick (18), wherein the vapor channels (21 ) are formed by the wick (18) itself or by an interface separate from the wick (18), said interface being interposed between the heater (20) and the wick (18);

- guiding channels (19), fluidly connected to the vapor channels (21 ) so that airflows (42) coming from the guiding channels (19) flows through the vapor channels (21 ) for carrying the aerosol to a vapor outlet (15) of the aerosol generating assembly (10); and

- a redistribution chamber (22), the guiding channels (19) being fluidly connected to the vapor channels (21 ) via the redistribution chamber (22), so that the airflows coming from the guiding channels (19) mixes in the redistribution chamber (22) before entering the vapor channels (21 ).

2. The heating system (50) according to claim 1 , wherein every guiding channel (19) and every vapor channel (21) open in the redistribution chamber (22).

3. The heating system (50) according to any one of the preceding claims, wherein the redistribution chamber (22) defines several individual redistribution zones (46), and wherein each redistribution zone (46) connects two or more of the guiding channels (19) to a single of the vapor channels (21 ), said two or more guiding channels (19) and single vapor channel (21 ) opening in the redistribution zone (46).

4. The heating system (50) according to any one of the preceding claims, wherein some or each of the guiding channels (19) are open offset relative to the vapor channels (21 ).

5. The heating system (50) according to any one of the preceding claims, wherein the number of the guiding channels (19) is equal to or greater than the number of the vapor channels (21 ), preferably at least twice of the number of the vapor channels (21 ).

6. The heating system (50) according to any one of the preceding claims, wherein the total cross-sectional area of the guiding channels (19) is substantially equal to the total cross-sectional area of the vapor channels (21 ).

7. The heating system (50) according to any one of the preceding claims, wherein each guiding channel (19) has a respective cross-sectional area substantially equal to the respective cross-sectional areas of the other guiding channels (19).

8. The heating system (50) according to any one of the preceding claims, wherein the guiding channels (19) are homogeneously distributed.

9. The heating system (50) according to any one of the preceding claims, wherein at least one bypass channel (48), separate from the vapor channels (21 ), is defined along the wick (18) and opens in the redistribution chamber (22) for connecting the redistribution chamber (22) to the vapor outlet (15) and wherein a cross-sectional area of the or each bypass channel is less than the respective cross-sectional areas of each vapor channel (21 ).

10. The heating system (50) according to any one of the preceding claims, wherein the vapor channels (21 ) are formed by the wick (18) itself.

11 . The heating system (50) according to any one of the preceding claims, wherein the vapor channels (21 ) are arranged along the wick (18), opposite to the absorbing surface (23) of the wick (18).

12. An aerosol generating assembly (10) comprising the heating system (50) according to any one of the preceding claims.

13. The aerosol generating assembly (10) according to claim 12, comprising:

- an aerosol generating device (12); and

- a cartridge (14), storing the liquid vaporizable material, the cartridge (14) being configured to be engaged with the aerosol generating device (12); the heating system (50) being integrated partially in the aerosol generating device (12) and partially in the cartridge (14) so that the liquid vaporizable material is in contact with the absorbing surface (23) when the cartridge (14) is engaged.

14. The aerosol generating assembly (10) according to any one of claims 12 and 13, further comprising an airflow inlet (1 1 ), the guiding channels (19) fluidly connecting the airflow inlet (1 1 ) to the redistribution chamber (22).

15. The aerosol generating assembly (10) according to any one of claims 12 to 14, further comprising a mouthpiece (17) forming the vapor outlet (15), the vapor channels (21) fluidly connecting the redistribution chamber (22) to the vapor outlet (15).