Aerosol generating device with vacuum insulation

Abstract

An aerosol generating device (100) is disclosed, comprising: an insulating material (103) having an inner wall (104) and an outer wall (106) separated from each other; a cavity (110) defined within the inner wall capable of receiving an aerosol-forming substance (10); and a heater (112) positioned to heat the aerosol-forming substance when it is received in the cavity, wherein a reflective coating (124) is provided on an outer surface (104b) of the inner wall, the reflective coating comprising a first layer and a second layer, the first layer and the second layer comprising different materials configured to reflect radiation of different wavelengths.

Description

[Technical Field]

[0001] The present invention relates to an aerosol generating device, and in particular to an aerosol generating device having vacuum insulation. [Background technology]

[0002] Aerosol generating devices can generate aerosols by heating an aerosol-forming substance using one or more heaters. Operating the heaters can be energy-intensive, especially in aerosol generating devices configured to heat tobacco in a heating oven. Such aerosol generating devices can also take several seconds to reach the aerosol-generating temperature, which can be inconvenient for users. Therefore, there is a demand for aerosol generating devices that are more efficient and can generate aerosol more quickly. In addition, there is a need to maintain the exterior surface of the aerosol generating device at a safe and comfortable temperature. Summary of the Invention [Problem to be solved by the invention]

[0003] The present invention aims to meet these needs. [Means for solving the problem]

[0004] According to a first aspect of the present invention, there is provided an aerosol generating device comprising: an insulating material having an inner wall and an outer wall separated from each other; a cavity defined within the inner wall capable of receiving an aerosol-forming substance; and a heater positioned to heat the aerosol-forming substance when received in the cavity, the heater having a reflective coating on an outer surface of the inner wall.

[0005] In this way, the reflective coating can inhibit the radiative transfer of heat from the inner wall to the outer wall, thus providing a more thermally efficient aerosol generating device. Reducing heat leakage from the cavity allows the cavity to reach aerosol generating temperatures more quickly. The insulating material also more effectively insulates the outer surface of the aerosol generating device, reducing the temperature of the outer surface during use. This provides a safer device that is more comfortable to hold.

[0006] Those skilled in the art will appreciate that the terms "inner" and "outer" as used herein refer to the wall (or wall surface) closest or farthest from the cavity, respectively.

[0007] Preferably, the inner and outer walls are separated from each other by a vacuum. In this way, the insulation is a vacuum insulation, which more effectively insulates the cavity. The use of a reflective coating with a vacuum insulation is particularly advantageous because vacuum insulation is very effective at reducing heat transfer by conduction, but is not effective at reducing heat transfer by radiation. It is believed that the reflective coating can reduce the amount of heat radiated from the outer surface of the inner wall.

[0008] In other exemplary embodiments, the insulation may include any suitable insulating medium, such as air.

[0009] Preferably, a reflective coating is also provided on the inner surface of the outer wall. In this way, heat radiated from the inner wall can be reflected back toward the inner wall, reducing heat leakage from the insulation. This further improves the efficiency of the aerosol generating device and reduces the temperature of the outer surface of the aerosol generating device. In addition, reducing heat leakage from the cavity allows the cavity to reach the aerosol generating temperature more quickly.

[0010] Preferably, the heater is provided on the outer surface of the inner wall, so that the heater can efficiently transfer heat to the cavity by conduction through the inner wall.

[0011] The heater may be disposed between the reflective coating and the inner wall, such that heat radiated from the surface of the heater towards the outer wall in the form of infrared radiation is reflected towards the inner wall, which further improves the thermal efficiency of the aerosol generating device.

[0012] In some embodiments, the heater is provided on the inner surface of the inner wall. A reflective coating may additionally be provided on the inner surface of the inner wall, and the heater may be provided on the reflective coating on the inner surface of the inner wall.

[0013] In other embodiments, the heater may be any form of heater arranged to heat the aerosol-generating material received within the cavity, as known in the art. For example, the heater may comprise an inductively or resistively heatable blade or rod positioned within the cavity to heat the aerosol-generating material. The blade or rod may be configured to penetrate the consumable containing the aerosol-generating material. Alternatively, the heater may include one or more inductive elements or an inductive arrangement configured to inductively heat the susceptor. The inductive elements may be disposed around the cavity. Alternatively, the inductive element or elements may be disposed within a consumable receivable within the cavity.

[0014] Preferably, the reflective coating comprises a layer of reflective paint. In one embodiment, a highly reflective white paint can be used. The use of white paint has been found to reduce the temperature of the exterior surface of the interior wall by up to 151°C in use. In another embodiment, a silver paint can be used.

[0015] Preferably the reflective coating comprises a layer of metal foil such as aluminium foil. Alternatively, silver foil can be used, which has been found to reduce the outer surface of the inner wall to 135°C in use.

[0016] The reflective coating may also comprise a vapor-deposited metal layer, such as vapor-deposited silver, gold, or aluminum.

[0017] Preferably, the reflective coating comprises a first layer and a second layer. The first layer and the second layer may comprise different materials. This may provide a more effective means of insulating the exterior wall from radiant heat. For example, the first and second layers may comprise different materials and therefore have reflectivity profiles that peak at different wavelengths so as to efficiently reflect radiation over a wider range of wavelengths.

[0018] Preferably, the first layer comprises a reflective paint and the second layer comprises a metal foil. This may provide a more effective means of insulating the exterior wall from radiant heat. In one embodiment, the paint may be a reflective white paint and the metal foil may be aluminum. This particular combination has been found to reduce the temperature of the exterior surface of the interior wall by up to 107°C in use.

[0019] Preferably, the aerosol-generating device is configured to heat an aerosol-generating material comprising tobacco. The heater may be configured to heat the cavity to a temperature below the combustion temperature of tobacco, and the cavity may be configured to receive a rod or elongated consumable comprising tobacco, thereby enabling the aerosol-generating device to function as a non-combustion heated device.

[0020] In some embodiments, a reflective coating may also be provided on the exterior wall. In this way, the efficiency of the insulation can be further improved. The reflective coating can be provided on the interior or exterior surface of the exterior wall. Alternatively, the coating can be provided on both the interior and exterior surfaces of the exterior wall.

[0021] According to a second aspect of the present invention, there is provided an aerosol generating device comprising: an insulating material having an inner wall and an outer wall separated from each other; a cavity defined within the inner wall capable of receiving an aerosol-forming substance; and a heater positioned to heat the aerosol-forming substance when received in the cavity, the heater having a reflective coating on the outer wall.

[0022] In this way, heat radiated from the inner wall can be reflected back towards the inner wall, reducing heat leakage through the insulation. This further improves the efficiency of the aerosol-generating device and reduces the temperature of the outer surface of the aerosol-generating device. In addition, reducing heat leakage from the cavity allows the cavity to reach the aerosol-generating temperature more quickly.

[0023] The second aspect of the invention may include any of the features discussed in relation to the first aspect of the invention above, such as vacuum insulation and / or a particular reflective coating.

[0024] Embodiments of the invention will now be described, by way of example, with reference to the drawings, in which: [Brief explanation of the drawings]

[0025] [Figure 1] 1 shows a schematic cross-sectional view of an aerosol generating device according to one embodiment of the present invention. [Figure 2] 1 shows a control diagram of an aerosol generating device according to one embodiment of the present invention. [Figure 3] 1 shows a cross-sectional schematic view of a heating device in use according to one embodiment of the present invention; [Figure 4] 1 shows a schematic diagram of a portion of a heating apparatus according to one embodiment of the present invention. [Figure 5] 1 shows a schematic plan view of a heating device according to one embodiment of the present invention; [Figure 6] 1 shows a schematic diagram of a portion of a heating apparatus according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0026] FIG. 1 shows a schematic diagram of an aerosol generating device 100 according to one embodiment of the present invention.

[0027] The aerosol generating device 100 includes a tubular housing 102 for enclosing and protecting the internal components of the aerosol generating device 100. A vacuum insulation 103 is provided and is surrounded by the inner wall 104 and the outer wall 106, with an inner wall 104, an outer wall 106, and an annular vacuum 108 separating the two. As discussed further below with reference to Figures 4 and 6, the vacuum insulation 103 includes a reflective coating that enhances the insulating properties of the vacuum insulation 103. A cavity 110 is defined in the inner wall 104 for receiving an aerosol-forming substance. An opening 111 is provided in the housing 102 and aligned with the cavity 110 to allow a user to insert the aerosol-forming substance into the cavity 110. A heater 112 is provided on the inner wall 104 and within the vacuum 108 for heating the aerosol-forming substance received in the cavity 110 by conduction through the inner wall 104.

[0028] A controller 114 is provided and configured to control the operation of the heater 112. A button 116 is provided on the housing 102 in electrical communication with the controller 114 to allow a user to initiate aerosol generation. A battery 118 is provided to provide power to the heater 112, the controller 114, and other electrical components of the aerosol generating device 100.

[0029] Figure 2 shows a control schematic of the aerosol generating device 100. The controller 114 comprises at least one processor 114a and memory 114b for executing and storing, respectively, executable instructions 114c for operating the components of the aerosol generating device 100. The controller 114 is electrically connected to receive or send operating signals to the components shown in Figure 2.

[0030] The housing 102 may comprise any suitable material known in the art, such as plastic or metal. In other embodiments, the button 116 may be replaced by or used in conjunction with any other suitable input mechanism, such as a fingerprint sensor or gesture sensor. The battery 118 may be permanently fixed within the housing 102 and may be rechargeable. Alternatively, the battery 118 may be removable. In other embodiments, the aerosol generating device may be provided without the battery 118, and the user may supply a separate battery pack or disposable power source.

[0031] 3, the vacuum insulation 103, the heater 112, and the cavity 110 form a heating apparatus 120. A rod-shaped consumable 10 comprising a tobacco 12 and a filter 14 is shown inserted into the cavity 110 as performed by a user prior to use of the aerosol generating device 100.

[0032] The heaters 112 are provided within the vacuum 108 at two separate locations on diametrically opposed portions of the inner wall 104. The heaters 112 comprise resistive tracks configured to generate heat when an electric current is applied, and the tracks are disposed on a film substrate that functions as an electrically insulating substrate. The film heaters are curved to match the curvature of the inner wall 104 and allow for good thermal contact with the inner wall 104. In alternative embodiments, the heaters 112 may be provided as any suitable heater capable of heating the consumable 10 within the cavity 110 to generate an aerosol. The heaters 112 may be provided as one or more curved heating films or tracks extending around the periphery of the inner wall 104. Alternatively, the heaters 112 may be provided as one or more heating films or tracks provided at spaced locations around the inner wall.

[0033] The heater 112 is configured to heat the inner wall 104 by conduction, thereby raising the temperature of the air within the cavity 110 to an aerosol-generating temperature. The consumable 10 may have a circumference that generally matches the circumference of the cavity 110, such that the consumable 10 contacts the inner wall 104 when placed within the cavity 110 by a user. The heater 112 heats the contents of the cavity 110 to a temperature sufficient to generate an aerosol using the tobacco 12 within the consumable 10. The heater 112 may be configured to heat the contents of the cavity 110 to a temperature below the combustion temperature of the tobacco 12, allowing the aerosol-generating device 100 to function as a so-called "non-combustion heated" device.

[0034] In other embodiments, the cavity 110 and heater 112 may be configured to receive and heat other forms of consumables, respectively, as known in the art. For example, the heater 112 may include an inductively heatable susceptor material configured to generate heat under the influence of an electromagnetic field. Such an electromagnetic field may be generated by an inductor unit provided at an appropriate location within the aerosol generating device 100. Alternatively, the susceptor material may be permanently located within the cavity 110 or may be provided within the consumable 10. The heater 112 may also take the form of a resistively or inductively heatable rod or blade positioned within the cavity 110 to penetrate the consumable 10.

[0035] 1 has an annular cylindrical shape with a circular cross section. Vacuum insulation 103 is hollow and encloses vacuum 108 between curved inner wall 104, curved outer wall 106, and substantially flat surfaces 122a-122c that confine vacuum 108 within inner wall 104 and outer wall 106. Flat surface 122a connects inner wall 104 to outer wall 106, while flat surfaces 122b and 122c close inner wall 104 and outer wall 106, respectively.

[0036] In other embodiments, the vacuum insulation 103 may have other shapes. For example, the vacuum insulation 103 may have a square or polygonal cross-section, or any other suitable cross-sectional shape. While the vacuum insulation 103 shown in FIGS. 1 and 3 has a cup shape with one open end and one closed end, the vacuum insulation 103 may also have a tubular shape with two open ends. In another example, the outer wall 106 may be directly bonded to the inner wall 104, lacking the connecting flat surface 122a, as shown in FIG. 3. The vacuum insulation 103 may be mechanically attached to the housing 102 by one or more mechanical bonds (not shown). The vacuum insulation 103 may comprise stainless steel, a heat-resistant plastic such as PEEK, or any other suitable material.

[0037] The heater 112, inner wall 104, and flat surface 122b collectively heat the consumable 10 via conduction and therefore may be collectively referred to as the "heater cup." The outer wall 106 and flat surface 122c enclose a vacuum 108 around the heater cup and therefore may be referred to as the "outer shell" or "vacuum chamber" of the heater cup. The heater cup and outer shell may comprise different materials. For example, the inner wall 104 and flat surface 122b may comprise a metal such as stainless steel, while the outer wall 106 and flat surface 122c may comprise an insulating material such as heat-resistant glass. The inner wall 104 and outer wall 106 may comprise any suitable material known in the art. The flat surface 122a may be integral with the heater cup or outer shell, or may be provided as a separate component joined to the inner and outer walls 104, 106.

[0038] In other exemplary embodiments, the vacuum insulation 103 may be replaced with other types of insulation. In one example, insulation may be provided with inner and outer walls that contain an insulating medium such as air, aerogel, and various foam or fibrous materials, rather than a vacuum 108.

[0039] An example of how the aerosol generating device 100 can be used will now be described with reference to FIG. 1 . During use, a user can insert the consumable 10 into the cavity 110 through the opening 111. The inner wall 104 holds the consumable 10 in place within the cavity 110 by friction. When the user is ready to begin vaporization, the user may press the button 116, which triggers the controller 114 to turn on the heater 112. The heater 112 provides heat to the contents of the cavity 110, including the consumable 10, while the vacuum 108 within the vacuum insulation 103 prevents heat from escaping from the cavity 110. The heating device 120 thus forms an oven capable of heating the tobacco 12 within the consumable 10 to a desired temperature. The controller 114 may be configured to instruct the heater 112 to heat the tobacco 12 to a temperature below the tobacco's combustion temperature. As the tobacco 12 is heated, an aerosol is generated within the cavity 110. A user can inhale the aerosol by drawing air through the filter 14, creating an airflow through the consumable 10 that carries the aerosol to the user.

[0040] Figure 4 shows a cross-sectional portion of a heating device 120 according to one embodiment of the present invention. The inner wall 104 has an inner surface 104a facing the cavity 110 and an outer surface 104b facing the vacuum 108. Similarly, the outer wall 106 has an inner surface 106a facing the vacuum 108 and an outer surface 106b facing the housing 102. Figure 5 shows a top view of the heating device 120 showing different surfaces of the inner and outer walls 104, 106 from different perspectives.

[0041] During use, the heater 112 heats the inner wall 104 to a temperature above approximately 100°C. The consumable 10 is in contact with the inner surface 104a, and therefore the consumable 10 is heated by conduction. The inner surface 104a also emits radiation, or "radiant heat," which can be absorbed by the consumable 10 to further heat the consumable 10. However, the outer surface 104b of the inner wall 104 can undesirably emit radiant heat toward the outer wall 106. This radiation can be absorbed by the outer wall 106 and then lost from the vacuum insulation 103 by conduction or radiation processes. The present invention provides a first reflective coating 124 on the outer surface 104b, as shown in FIG. 4, thus minimizing heat loss from the vacuum insulation 103.

[0042] The first reflective coating 124 can reflect radiation received from the outer surface 104b. In addition, the reflective coating 124 can suppress radiation emission from the outer surface 104b, thereby providing more efficient thermal insulation for the aerosol-generating device 100. Additionally, the consumable 10 reaches the aerosol-generating temperature more quickly because less heat can escape from the cavity 110.

[0043] 1-5, the first reflective coating 124 is provided on all of the interior wall 104 and flat surface 122b (i.e., on all of the "heater cups"). In other embodiments, the first reflective coating 124 may be provided on only a portion of the interior wall 104, such as only the portion of the interior wall 104 and flat surface 122b that is exposed to the vacuum 108. In a further embodiment, shown in FIG. 6, the first reflective coating 124 may be provided on the heater 112 such that the heater 112 is encapsulated between the first reflective coating 124 and the interior wall 104. This may reduce emissions from the heater 112 toward the interior surface 106a of the exterior wall 106, further improving the efficiency and reducing heat-up time of the consumable 10.

[0044] A second reflective coating 126 is also provided on the inner surface 106a of the outer wall 106. The second reflective coating 126 reflects radiation that reaches the outer wall 106 (despite the first reflective coating 124) towards the cavity 110, thereby further improving efficiency and reducing the heating time of the consumable 10.

[0045] A second reflective coating 126 may similarly be provided on some or all of the inner wall 106 and flat surface 122c (i.e., the "outer shell"). The second reflective coating 126 may comprise the same or a different material as the first reflective coating 124. In other embodiments, only one of the first reflective coating 124 and the second reflective coating 126 is provided.

[0046] The first reflective coating 124 and the second reflective coating 126 can comprise any suitable material. Some exemplary materials that can be used include paints, such as white, silver, or other metallic paints; metals, such as metal foils, including silver, aluminum, and gold; vapor-deposited metal layers, such as vapor-deposited silver, aluminum, or gold; or glazes, such as Heraeus glaze. The metal layer may be provided with an oxide protective layer, although this may not be required in the vacuum insulation material 103. The reflective properties of gold, silver, and aluminum for various wavelengths are shown in Table 1 below. The first reflective coating 124 and / or the second reflective coating 126, when comprised of the corresponding materials, can have at least the reflectivity levels shown in Table 1.

[0047] [Table 1]

[0048] The first reflective coating 124 and / or the second reflective coating 126 can also comprise a first layer having a first material and a second layer having a second material. In one embodiment, the first reflective coating 124 can comprise white paint applied to the exterior surface 104b and aluminum foil wrapped around the exterior surface 104b above or below the heater 112. In other embodiments, any combination of two or more of the materials discussed above can be used in the first or second reflective coatings 124, 126.

[0049] Table 2 shows the temperature of the exterior surface 104b when the heater is turned on for different material choices for the first reflective coating 124. As shown, the combination of white paint and aluminum foil has been found to be particularly effective in reducing the temperature of the exterior surface 104b (and therefore reducing the radiative transfer of heat to the exterior wall 106).

[0050] [Table 2]

[0051] In some embodiments, a reflective coating may be provided on the outer surface 106b of the exterior wall 106 to further insulate the cavity 110. The outer surface 106b may be coated with any of the materials discussed above with respect to the first or second reflective coatings 124, 126.

[0052] In a further embodiment, a reflective coating may be provided on the inner surface 104a in addition to the outer surface 104b, in which case the heater 112 is positioned on the inner surface 104a covering the reflective coating of the inner surface 104a, instead of being positioned on the outer surface 104b within the vacuum 108.

Claims

1. 1. An aerosol generating device comprising: an insulation material having an inner wall and an outer wall separated from each other; a cavity defined within the inner wall capable of receiving an aerosol-forming substance; a heater positioned to heat the aerosol-forming material when it is received in the cavity, the heater having a reflective coating on an outer surface of the inner wall; the reflective coating comprises a first layer and a second layer, the first layer and the second layer comprising different materials configured to reflect radiation of different wavelengths. Aerosol generating devices.

2. The aerosol generating device of claim 1 , wherein the inner wall and the outer wall are separated from each other by a vacuum.

3. 3. The aerosol generating device according to claim 1, wherein the reflective coating is provided on the inner surface of the outer wall.

4. The aerosol generating device according to any one of claims 1 to 3, wherein the heater is provided on the outer surface of the inner wall.

5. The aerosol generating device according to claim 4 , wherein the heater is provided between the reflective coating and the inner wall.

6. The aerosol generating device according to any one of claims 1 to 3, wherein the heater is provided on the inner surface of the inner wall.

7. 7. The aerosol generating device of claim 6, wherein the reflective coating is also provided on the inner surface of the inner wall, and the heater is provided on the reflective coating.

8. 8. An aerosol generating device according to claim 1, wherein the reflective coating comprises a layer of reflective paint.

9. 9. An aerosol generating device according to claim 1, wherein the reflective coating comprises a layer of metal foil, such as aluminum foil.

10. 10. The aerosol generating device according to claim 1, wherein the reflective coating is provided on the outer wall.

11. An aerosol generating device according to any one of claims 1 to 10, configured to heat an aerosol-generating material comprising tobacco.

12. 1. An aerosol generating device comprising: an insulation material having an inner wall and an outer wall separated from each other; a cavity defined within the inner wall capable of receiving an aerosol-forming substance; a heater positioned to heat the aerosol-forming material when it is received in the cavity, the heater having a reflective coating on the outer wall; the reflective coating comprises a first layer and a second layer, the first layer and the second layer comprising different materials configured to reflect radiation of different wavelengths. Aerosol generating devices.

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