Heating assembly for an aerosol generating device - Patent application

Abstract

A heating assembly for an aerosol generating device comprising a heating chamber (25) having an opening for receiving an aerosol substrate, the heating chamber (25) comprising a first tubular portion (14) made of a ceramic material, at least one second tubular portion (20) made of a metallic material or a heat-resistant plastic, and a heating element (16) configured to heat the first tubular portion (14), the at least one second tubular portion (20) being connected to an end of the first tubular portion (14).

Description

[Technical field]

[0001] The present disclosure relates to a heating assembly for an aerosol generating device, and to an aerosol generating device comprising such a heating assembly. The present disclosure is particularly applicable to portable aerosol generating devices that may be self-contained and cryogenic. [Background technology]

[0002] To heat the aerosol substrate, a heating assembly is known that includes a heating chamber for receiving the aerosol substrate and a heating element for heating the heating chamber. The heating chamber is generally wrapped with a metal thin film heater. However, this heating chamber is not entirely satisfactory.

[0003] Other heating chambers are made from materials that have properties that enhance heating of the aerosol substrate and thus improve the user experience. For example, heating chambers made from ceramic materials are known.

[0004] However, these heating chambers require a great deal of energy to reach the aerosolization temperature, and the heat is distributed uniformly and cannot be targeted to specific areas of the heating chamber. Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention first aims to overcome at least some of the shortcomings of the prior art. It is also an object of the present invention to provide a heating chamber that provides sufficient heat penetration while focusing heat on specific areas of the heating assembly. [Means for solving the problem]

[0006] The present invention therefore relates to a heating assembly for an aerosol generating device comprising a heating chamber having an opening for receiving an aerosol substrate, said heating chamber comprising a first tubular portion made of a ceramic material, at least one second tubular portion made of a metallic material or a heat-resistant plastic, and a heating element configured to heat said first tubular portion, wherein the at least one second tubular portion is connected to an end of the first tubular portion.

[0007] Heat-resistant plastics, also known as heat-resistant plastics, refer in the present invention to polymeric materials that have a relatively high resistance to heat, for example above 100°C or 150°C.

[0008] In the heating assembly according to the invention, a first tubular portion is connected at one of its longitudinal ends to a second tubular portion to form a tubular assembly comprising a ceramic portion joined to a metallic material portion or a heat-resistant plastic portion.

[0009] In other words, the heating chamber comprises a junction or interface between a first tubular portion made of ceramic and at least one second tubular portion made of a metallic material or a heat resistant plastic.

[0010] The connection between the first tubular portion made of a ceramic material and the second tubular portion made of a metallic material or a heat-resistant plastic creates an area of ​​varying thermal resistance, leading to the formation of a thermal break, which reduces or even prevents the diffusion of heat towards the longitudinal ends of the first tubular portion.

[0011] When the heating element heats the first tubular portion, the heat diffuses except toward the interface or junction with the second tubular portion. Thus, the heat is concentrated in a portion of the first tubular portion that is located away from the second tubular portion, and more particularly away from the junction or interface between the first and second portions. In other words, the junction or interface with the ceramic and metal material or heat resistant plastic at the longitudinal end of the first tubular portion concentrates the heat in a particular area of ​​the first tubular portion.

[0012] It is known that ceramics have a high thermal mass, so that ceramic materials require more energy to reach a certain temperature than metallic tubular parts. By adding at least one second tubular part of metallic material or heat-resistant plastic to the longitudinal end of the first tubular part, it is possible to reduce the total thermal mass of the first tubular part and thus the energy consumption to reach a certain temperature.

[0013] Moreover, the use of ceramic materials in the heating chamber allows for better heat penetration into the tobacco, which translates into improved sensory performance with more vapor and higher nicotine levels depending on the aerosol base.

[0014] Particularly simple, convenient and economical preferred features of the heating assembly according to the present invention are presented below.

[0015] The second tubular portion may be made of stainless steel or polyetheretherketone (PEEK), in other words, the metallic material may be stainless steel, while the heat resistant plastic may be PEEK.

[0016] The metal material may also be copper or aluminum. The heat-resistant plastic may also be other engineering plastics such as polyetherimide (PEI) or polyphenylene sulfide (PPS). The second tubular portion may be abutted against said end of the first tubular portion.

[0017] The first tubular portion may have a thinned end portion forming a shoulder, and at least one second tubular portion has an end portion that bears against said shoulder.

[0018] At least one second tubular portion may cover a circumferential surface of a first tubular portion located at an end side of said first tubular portion.

[0019] In other words, at least a portion of the second tubular portion completely surrounds a surface of the first tubular portion.

[0020] The circumferential surface of the first tubular portion that is covered by the second tubular portion may be an inner surface of the first tubular portion.

[0021] The first tubular portion and the at least one second tubular portion may be connected by an interference fit.

[0022] The first tubular portion and the at least one second tubular portion may be sealed. By "sealed" is meant any manner by which the first tubular portion is joined to the at least one second tubular portion in a liquid-tight manner. Thus, the first tubular portion and the second tubular portion may be sealed by brazing, welding, gluing, screwing, riveting, shrinking, or applying a sealant, for example a high temperature silicone-based sealant.

[0023] The first tubular portion may occupy between 10% and 90% of the length of the heating chamber. Preferably, the first tubular portion occupies approximately 50% of the length of the heating chamber.

[0024] The ceramic material of the first tubular portion may be aluminum nitride (AlN), silicon carbide (SiC), silicon nitride (Si2N4), or beryllium oxide (BeO). In this application, aluminum nitride is preferred.

[0025] The heating element may be formed in a meandering pattern on the first tubular portion.

[0026] The first tubular portion includes one or more flat regions extending axially of the heating chamber.

[0027] The heating assembly may comprise two second tubular portions each connected to the first tubular portion at a first end of the first tubular portion and at a second end of the first tubular portion axially opposite the first end, the two second tubular portions being spaced apart in the axial direction of the heating chamber.

[0028] The second tubular portion may be made from stainless steel or PEEK (polyetheretherketone).

[0029] With the two second tubular portions axially located at opposite ends of the first tubular portion, heat is more concentrated in the first tubular portion.

[0030] A second tubular portion may abut the first end and the second end of the first tubular portion.

[0031] The first tubular portion may be centrally located between a first end of the heating chamber and a second end of the heating chamber axially opposite the first end.

[0032] The heating element may extend axially on the first tubular portion between the second tubular portions.

[0033] According to another aspect, the present invention relates to an aerosol generating device comprising a battery and a heating assembly as described above, wherein said heating element is powered by the battery.

[0034] The aerosol generating device offers the same advantages as those described in relation to the heating assembly.

[0035] Other particularities and advantages of the invention will become apparent from the following description.

[0036] The accompanying drawings, given by way of non-limiting example, are: [Brief description of the drawings]

[0037] [Figure 1] 1 shows an aerosol generating device, represented diagrammatically semi-transparently, comprising a battery and a heating assembly according to the invention. [Diagram 2] FIG. 2 is a perspective view of a heating assembly according to certain embodiments of the present invention. [Diagram 3] 3 is a cross-sectional view of the heating assembly taken along axis A shown in FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0038] 1 depicts an aerosol generating device 1 according to one embodiment. The aerosol generating device 1 is shown in an assembled configuration to allow the internal components to be viewed. The aerosol generating device 1 is a heated non-combustion device, sometimes referred to as a tobacco vapor device, and includes a heating assembly 10 and a battery electrically connected to the heating assembly 10.

[0039] The heating assembly 10 is configured to receive an aerosol substrate, such as a rod of aerosol-generating material, e.g., tobacco. The heating assembly is also configured to convert electrical energy provided by the battery 5 into thermal energy. To this end, the heating assembly 10 is operable to heat, rather than combust, a rod of aerosol-generating material to generate a vapor or aerosol for inhalation by a user. Of course, those skilled in the art will appreciate that the aerosol generating device 1 shown in FIG. 1 is merely an exemplary aerosol generating device according to the present invention. Other types and configurations of tobacco vapor products, vaporizers, or e-cigarettes may also be used as aerosol generating devices according to the present invention.

[0040] The heating assembly 10, according to one embodiment, is best seen in Figures 2 and 3.

[0041] The heating assembly 10 comprises a heating chamber 25, also referred to as a thermally conductive shell, configured to hold an aerosol substrate, also referred to as a consumable. In particular, the heating chamber 25 defines a generally cylindrical cavity in which a rod of aerosol substrate can be positioned. The heating chamber 25 is tubular, e.g., generally cylindrical, and defines a central passage 13 that opens into a first end 11 of the heating chamber 25 and into a second end 12 of the heating chamber 25 axially opposite the first end 11. In other words, the central passage 13 is accessible through an opening from each of the first end 11 and the second end 12.

[0042] Alternatively, the central passage may have only one opening located at either the first or second end of the heating chamber.

[0043] During use, a user may insert an aerosol substrate through an opening in heating chamber 25 such that the aerosol substrate is positioned within heating chamber 25 and contacts the inner surface of heating chamber 25. The length of heating chamber 25 may be configured such that a portion of the aerosol substrate can protrude from heating chamber 25 through the opening, i.e., outside heating assembly 10, and be received by the user's mouth.

[0044] According to a particular embodiment of the present invention, the heating chamber 25 includes a first tubular portion 14 and two second tubular portions 20 connected to the first tubular portion 14 .

[0045] Alternatively, the heating chamber 25 may include a first tubular portion and only one second tubular portion connected to one end of the first tubular portion.

[0046] The first tubular portion 14 here has a circular cross section and has a first end and a second end axially opposite the first end, in other words, the first tubular portion 14 is tubular, e.g., substantially cylindrical.

[0047] Alternatively, the first tubular portion may be generally cylindrical, but with one or more flat regions extending axially of the heating chamber.

[0048] The first tubular portion 14 is made from a ceramic material, more particularly from aluminum nitride (abbreviated AlN) in the example shown.

[0049] Due to the construction of the first tubular portion made of ceramic material, the first tubular portion 14 has a high thermal mass, which provides good heat penetration into the aerosol substrate, especially when said aerosol substrate comprises tobacco, which allows for improved sensory performance with higher vapor and higher nicotine levels when the aerosol substrate contains tobacco.

[0050] The first tubular portion 14 comprises, at its first and second ends, a thinned end portion 15. The thinned end portion 15 has a thickness that is smaller than the thickness of the remainder of the first tubular portion 14. In particular, the inner diameter of the first tubular portion 14 at the thinned end portion 15 is larger than the inner diameter of the remainder of the first tubular portion 14. In other words, the first tubular portion 14 is provided with a counterbore at its first and second ends.

[0051] Alternatively, the inner diameter of the first tubular portion may be constant along the entire length of the first tubular portion, while the outer diameter at the thinned end portion may be smaller than the outer diameter of the remainder of the first tubular portion.

[0052] The change in diameter at the thinned end portion 15 of the first tubular portion 14 forms a shoulder 19. In the illustrated example, the shoulder 19 is formed on the inner surface 18 of the first tubular portion 14.

[0053] Alternatively, the shoulder may be formed on an outer surface of the first tubular portion.

[0054] The thinned end portions 15 extend to a length between 15% and 25% of the length of the first tubular portion 14. In particular, each thinned portion 15 has a length in the longitudinal direction of the first tubular portion 14 of between 0.25 mm and 2 mm, preferably between 0.75 mm and 1.5 mm, more preferably equal to 1 mm.

[0055] The thinned end portion 15 has a thickness of between 0.10 mm and 0.5 mm. The first tubular portion 14, over the remainder of its length, ie excluding the thinned end portion, has a thickness of between 0.15 mm and 0.75 mm.

[0056] The heating assembly 10 comprises a heating element 16 configured to function as a Joule heater when supplied with an electric current. In other words, the heating element 16 is configured to emit heat in response to the flow of electric current. This physical phenomenon may be referred to as Joule heating, resistive heating, or ohmic heating. In use, power may be provided to the heating element 16, for example from the battery 5, such that the temperature of the heating element 16 increases and thermal energy is transferred throughout the heating chamber 25, and more particularly to the first tubular portion 14. An aerosol substrate received within the heating assembly 1 is conductively heated by the heating chamber 25 to generate an aerosol for inhalation by a user.

[0057] The heating element 16 is here located on the outer surface 17 of the first tubular portion 14. Alternatively, the heating element may be integrated into the first tubular portion, i.e. located between the inner and outer surfaces of the first tubular portion. According to another alternative, the heating element may be located at a distance from the first tubular portion, i.e. without direct contact, and transfer heat, for example by convection.

[0058] The heating element 16 is here formed as a coating in a meander or serpentine pattern on the outer surface 17 of the first tubular portion 14. For example, the heating element 16 may be shaped by etching, masking, or laser cutting to form the illustrated pattern. Of course, one skilled in the art will appreciate that the specific pattern formed by the heating element 16 may vary depending on the functional requirements of the heating assembly 1. The pattern forms an electrical path such that, in use, electrical current supplied from the battery 5 to the heating element 16 travels along the electrical path and generates thermal energy. The heating element 16 is made from any material that functions as a Joule heater when supplied with electrical current, such as tungsten. Other materials having a thermal expansion coefficient that substantially matches that of the ceramic material may also be considered.

[0059] The second tubular portions 20 here have a circular cross section and each have a first end and a second end axially opposite the first end, in other words, the second tubular portions 20 are tubular, for example substantially cylindrical.

[0060] Alternatively, the second tubular portion may be generally cylindrical but may include one or more flat regions extending axially of the heating chamber.

[0061] Each second tubular portion 20 has a constant cross-section, i.e., the outer and inner diameters of the second tubular portion are constant along the length of the second tubular portion.

[0062] Alternatively, the second tubular portion has a thinned end portion similar to the thinned end portion described for the first tubular portion located at one end of the second tubular portion. If the second tubular portion has a thinned portion, the first tubular portion may not have a thinned end portion.

[0063] The second tubular portion 20 has a thickness of 0.05 mm to 0.15 mm.

[0064] The second tubular portion 20 is made of a metal material or a heat-resistant plastic, for example, a metal material such as stainless steel, copper, aluminum, or other suitable material, and a heat-resistant plastic such as an engineering plastic such as polyetherimide (PEI), polyphenylene sulfide (PPS), or polyetheretherketone (PEEK).

[0065] In some instances, PEEK may be preferred over stainless steel due to its thermal expansion properties more similar to the ceramic material of first tubular portion 14 .

[0066] As shown in FIGS. 2 and 3, the second tubular portions 20 are each connected to one end of the first tubular portion 14 .

[0067] In the illustrated embodiment, each second tubular portion 20 is at least partially inserted into the first tubular portion 14 at the location of the thinned portion 15. The second tubular portion 14 is inserted with a translational movement along the longitudinal direction of the first tubular portion 14 until the second tubular portion 20 contacts the shoulder 19. The second tubular portions 20 are thus axially spaced apart from one another by the first tubular portion 14. The second tubular portions 20 thus abut against the first and second ends of the first tubular portion 14.

[0068] The thinned end portion 15 of the first tubular portion 14 circumferentially surrounds at least a portion of the second tubular portion 20. In other words, the thinned end portion 15 at least partially overlaps a portion of the second tubular portion 20. Accordingly, at least a portion of the second tubular portion 20 overlaps the inner surface 18 of the first tubular portion 14 at the location of the thinned end portion 15.

[0069] Alternatively, at least a portion of the second portion covers an outer surface of the first tubular portion at the location of the thinned portion or at the end of the first tubular portion if the first tubular portion does not have a thinned portion.

[0070] Each second tubular portion 20 is inserted into the first tubular portion 14 with an interference fit. The interference fit reduces vapor leakage and therefore helps to deliver a larger amount of aerosol to the user. The interference fit also improves the contact and heat exchange between the first tubular portion 14 and the second tubular portion 20. Thus, there is at least one contact area between the first tubular portion 14 and the second tubular portion 20. In particular, the first contact area is located between the shoulders 19 and the surfaces of each second tubular portion 20 that bear against these shoulders 19. The second contact area is formed between the inner surface 18 of the first tubular portion 14 at the location of the tapered portion 15 and a part of the outer surface 22 of the second tubular portion 20. The second contact area is preferably circumferential.

[0071] To provide an interference fit, the outer diameter of the second tubular portion 20 is slightly less than or equal to the inner diameter of the first tubular portion 14 at the tapered section 15 .

[0072] Alternatively, the outer diameter of the first tubular portion is smaller than the inner diameter of the second tubular portion at the thinned end portion, which is applicable when the second tubular portion comprises a thinned end portion or when the first tubular portion comprises a thinned end portion and the shoulder is located on the outer surface.

[0073] Alternatively, the first and second tubular portions may be joined by threading if the inner or outer circumferential surface at the location of the thinned end portion is threaded. If the first tubular portion comprises a tapered end portion, the inner or outer circumferential surface of the second tubular portion is threaded to cooperate with the thread of the circumferential surface of the thinned end portion. If the second tubular portions each comprise a thinned end, the inner or outer surface of the first tubular portion is threaded to cooperate with the thread of the circumferential surface of the thinned end portion.

[0074] Alternatively, neither the first nor the second tubular portion has a thinned end portion. In this case, the portions are secured end-to-end, i.e., by their end faces, without overlapping the circumferential surface of the first tubular portion. The portions can be held therebetween, for example, by gluing, welding, or locating pins. Of course, one skilled in the art will appreciate that the specific means for assembling the first tubular portion 14 and the second tubular portion 20 can vary depending on the functional requirements of the heating chamber 25.

[0075] Once assembled, the first tubular portion 14 and the second tubular portion 20 are sealed together. In the illustrated example, the first tubular portion 14 is sealed to the second tubular portion 20 by brazing.

[0076] The seal further reduces the risk of aerosol leakage between the first tubular portion 14 and the second tubular portion 20 .

[0077] Because the first tubular portion 14 and the second tubular portion 20 have substantially equal inner diameters, except for the thinned portions, when assembled, the passageway 13 of the heating assembly 10 has a substantially constant cross-section. Among other things, this allows for improved aerosol flow within the heating assembly 10.

[0078] The second tubular portion 20 has a length along the longitudinal axis A of the heating chamber 25 that is shorter than the length of the first tubular portion 14. In particular, the cumulative length of the second tubular portion 20 is between 10% and 90%, preferably about 50%, of the overall length of the heating assembly 10.

[0079] In the illustrated example, the second tubular portions 20 are identical and therefore have the same length. The first tubular portion 14 is therefore centrally located in the heating assembly 10. In other words, the first tubular portion 14 is centrally located with respect to the first end 11 and the second end 12 of the heating assembly 10.

[0080] When the heating element 16 is powered by an electrical current provided by the battery 5 of the aerosol generating device 1, the heating element 16 converts electrical energy into heat, which is transferred by conduction to the first tubular portion 14. Due to the assembly of the first tubular portion 14 and the second tubular portion 20 as described above, heat is concentrated in the center of the first tubular portion 14, i.e. between the ends.

[0081] According to the present invention, the heating assembly 10, and more particularly the first tubular portion 14 made of ceramic material, requires less electrical energy to reach a given temperature compared to a heating assembly formed, for example, by a single ceramic tube. In addition, the present invention provides a heating assembly with a ceramic material portion, thus improving heat penetration and focusing heat transfer compared to a thin metal film.

Claims

1. 1. A heating assembly for an aerosol generating device comprising a heating chamber (25) having an opening for receiving an aerosol substrate, the heating chamber (25) comprising: a first tubular portion (14) made from a ceramic material; At least one second tubular portion (20) made from a metallic material or a heat-resistant plastic; a heating element (16) configured to heat the first tubular portion (14); Equipped with said at least one second tubular portion (20) is connected to an end of said first tubular portion (14); Heating assembly.

2. The heating assembly of claim 1, wherein the second tubular portion (20) is made from stainless steel or PEEK (polyetheretherketone).

3. 3. The heating assembly of claim 1 or 2, wherein the second tubular portion (20) is abutted against the end of the first tubular portion (14).

4. 4. A heating assembly according to claim 1, wherein the first tubular portion (14) has a thinned end portion (15) forming a shoulder (19) and the at least one second tubular portion (20) has an end portion that bears against the shoulder (19).

5. The heating assembly according to any one of claims 1 to 4, wherein the at least one second tubular portion (20) covers a circumferential surface of the first tubular portion (14) located on the end side of the first tubular portion (14).

6. 6. The heating assembly of claim 5, wherein the circumferential surface of the first tubular portion (14) covered by the at least one second tubular portion (20) is an inner surface (18) of the first tubular portion (14).

7. The heating assembly of any one of claims 1 to 6, wherein the first tubular portion (14) and the at least one second tubular portion (20) are connected by an interference fit.

8. The heating assembly according to any one of the preceding claims, wherein the first tubular portion (14) and the second tubular portion (20) are sealed together, preferably by brazing.

9. A heating assembly according to any one of claims 1 to 8, wherein the first tubular portion (14) occupies between 10% and 90% of the length of the heating chamber (25), preferably about 50% of the length of the heating chamber (25).

10. The heating assembly according to any one of the preceding claims, wherein the ceramic material of the first tubular portion (14) is aluminum nitride.

11. The heating assembly of any one of claims 1 to 10, wherein the heating element (16) is formed in a meandering pattern on the first tubular portion (14).

12. The heating assembly of any one of claims 1 to 11, wherein the first tubular portion (14) comprises one or more flat areas extending in an axial direction of the heating chamber (25).

13. 13. The heating assembly according to claim 1, further comprising two second tubular portions (20) connected to the first tubular portion (14) at a first end of the first tubular portion (14) and at a second end of the first tubular portion (14) axially opposite to the first end, the two second tubular portions (20) being spaced apart in the axial direction of the heating chamber (25).

14. 14. The heating assembly of claim 13, wherein the first tubular portion (14) is centrally located between a first end of the heating chamber (25) and a second end of the heating chamber (25) axially opposite the first end.

15. The heating assembly of claim 13 or 14, wherein the heating element (16) extends axially on the first tubular portion (14) between second tubular portions (20).

16. 2. The heating assembly of claim 1, comprising two second tubular portions (20), each connected to the first tubular portion (14) at a first end of the first tubular portion (14) and at a second end of the first tubular portion (14) axially opposite to the first end, the two second tubular portions (20) being spaced apart in the axial direction of the heating chamber (25), the second tubular portions (20) being made of stainless steel or PEEK (polyetheretherketone).

17. An aerosol generating device comprising a battery (5) and a heating assembly (10) according to any one of claims 1 to 16, wherein the heating element (16) is powered by the battery (5).

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