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. In particular, the present invention relates to an aerosol-generating device having a vacuum heat insulating material.

Background Art

[0002] An aerosol-generating device can generate an aerosol by heating an aerosol-forming substance using one or more heaters. Operating the heater can be energy-intensive, particularly in aerosol-generating devices configured to heat tobacco in a heating oven. Such aerosol-generating devices may also take several seconds to reach the aerosol-generating temperature, which can be inconvenient for a user. Therefore, there is a need for an aerosol-generating device that is more efficient and can generate aerosol more quickly. In addition, there is a need to maintain the outer surface of the aerosol-generating device at a safe and comfortable temperature.

Summary of Invention

Problem to be Solved by Invention

[0003] An object of the present invention is to address 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: a heat insulating material including an inner wall and an outer wall separated from each other; a cavity defined inside the inner wall, the cavity being capable of receiving an aerosol-forming substance; and a heater positioned to heat the aerosol-forming substance when it is received in the cavity, wherein a reflective coating is provided on an outer surface of the inner wall.

[0005] In this way, the reflective coating suppresses the radiative transfer of heat from the inner wall to the outer wall, thus providing a more thermally efficient aerosol generating device. Reduced heat leakage from the cavity allows the cavity to reach the aerosol generation temperature more quickly. The insulation also more effectively insulates the outer surface of the aerosol generating device, lowering 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 correctly recognize that the terms “inside” and “outside” as used herein refer to the wall (or wall surface) closest to or furthest 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 vacuum insulation is particularly advantageous because while vacuum insulation is highly effective in reducing heat transfer by conduction, it is not effective in reducing heat transfer by radiation. The reflective coating is thought to be able to reduce the amount of heat radiated from the outer surface of the inner wall.

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

[0009] Preferably, the reflective coating is also provided on the inner surface of the outer wall. In this way, heat radiated from the inner wall is reflected back to the inner wall, suppressing heat leakage from the insulation material. This further improves the efficiency of the aerosol generating device and lowers the temperature of the outer surface of the aerosol generating device. In addition, the reduction in heat leakage from the cavity allows the cavity to reach the aerosol generation temperature more quickly.

[0010] Preferably, the heater is mounted on the outer surface of the inner wall. In this way, the heater can efficiently transfer heat to the cavity by conduction through the inner wall.

[0011] The heater may be placed between the reflective coating and the inner wall. In this way, the heat radiated from the surface of the heater toward the outer wall in the form of infrared radiation is reflected toward the inner wall. This 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 be provided additionally on the inner surface of the inner wall, and the heater can be provided on the reflective coating on the inner surface of the inner wall.

[0013] In other embodiments, the heater can be any form of heater arranged to heat an aerosol-generating material received in the cavity, as is known in the art. For example, the heater may comprise an induction or resistance-heatable blade or rod positioned within the cavity to heat the aerosol-generating material. The blade or rod may be configured to penetrate a consumable containing the aerosol-generating material. Alternatively, the heater may include an induction arrangement configured to inductively heat one or more induction elements or susceptors. The induction elements may be located around the cavity. Alternatively, one or more induction elements may be located inside a consumable that can be received inside the cavity.

[0014] Preferably, the reflective coating comprises a layer of reflective paint. In one embodiment, a high-reflectance white paint can be used. It has been found that the use of white paint lowers the temperature of the outer surface of the inner wall to 151°C during use. In another embodiment, a silver paint can be used.

[0015] Preferably, the reflective coating comprises a layer of metal foil, such as aluminum foil. Alternatively, silver foil can be used, which has been shown to lower the temperature of the outer surface of the inner wall to 135°C during use.

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

[0017] Preferably, the reflective coating comprises a first layer and a second layer. The first and second layers may be made of 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 be made of different materials and therefore may have reflective profiles that peak at different wavelengths so that radiation can be efficiently reflected 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 can be a reflective white paint and the metal foil can be aluminum. This particular combination has been found to reduce the temperature of the exterior surface of the interior wall to 107°C during use.

[0019] Preferably, the aerosol generating device is configured to heat an aerosol generating substance comprising tobacco. The heater may be configured to heat the cavity to a temperature lower than the combustion temperature of the tobacco, and the cavity may be configured to receive a rod or elongated consumable comprising tobacco. This allows the aerosol generating device to function as a non-combustion heating device.

[0020] In some embodiments, the 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 inner or outer surface of the exterior wall. Alternatively, the coating can be provided on both the inner and outer surfaces of the exterior wall.

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

[0022] In this way, heat radiated from the inner wall can be reflected back toward the inner wall, thereby suppressing heat leakage from the heat insulator. 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, the reduction in heat leakage from the cavity allows the cavity to reach the aerosol generation temperature more rapidly.

[0023] The second aspect of the present invention may include any of the features discussed in connection with the first aspect of the present invention described above, such as an insulator that is a vacuum heat insulator and / or a specific reflective coating.

[0024] Here, embodiments of the present invention will be described by way of example with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] [Figure 1] 1 is a schematic cross-sectional view of an aerosol-generating device according to an embodiment of the present invention. [Figure 2] 2 is a schematic control diagram of an aerosol-generating device according to an embodiment of the present invention. [Figure 3] 3 is a schematic cross-sectional view of a heating device in use according to an embodiment of the present invention. [Figure 4] 4 is a partial schematic view of a heating device according to an embodiment of the present invention. [Figure 5] 5 is a schematic plan view of a heating device according to an embodiment of the present invention. [Figure 6] 6 is a partial schematic view of a heating device according to an embodiment of the present invention. [Modes for carrying out the invention]

[0026] Figure 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 housing and protecting the internal components of the aerosol generating device 100. A vacuum insulator 103 is provided and comprises an inner wall 104, an outer wall 106, and an annular vacuum 108 separating the two, and is enclosed by the inner wall 104 and the outer wall 106. As will be further discussed below with reference to Figures 4 and 6, the vacuum insulator 103 is provided with a reflective coating to improve the thermal insulation properties of the vacuum insulator 103. A cavity 110 is defined within the inner wall 104 to receive aerosol-forming material. An opening 111 is provided in the housing 102 and aligned with the cavity 110 to allow a user to insert aerosol-forming material into the cavity 110. A heater 112 is provided on the inner wall 104 and within the vacuum 108 to heat the aerosol-forming material 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 and electrically connected to the controller 114 to allow the user to start aerosol generation. A battery 118 is provided to power the heater 112, the controller 114, and other electrical components of the aerosol generating device 100.

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

[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 with 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 inside the housing 102 and 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 supply.

[0031] As shown in Figure 3, the vacuum insulation material 103, heater 112, and cavity 110 form the heating device 120. The rod-shaped consumable 10, comprising the tobacco 12 and filter 14, is shown inserted into the cavity 110, as performed by the user before use of the aerosol generating device 100.

[0032] The heater 112 is located inside the vacuum 108 at two separate locations on opposite portions of the inner wall 104. The heater 112 includes resistive tracks configured to generate heat when an electric current is supplied, and these tracks are arranged on a film substrate that serves as an electrical insulating substrate. The film heater is curved to match the curvature of the inner wall 104 to allow good thermal contact with the inner wall 104. In an alternative embodiment, the heater 112 may be provided as any suitable heater capable of heating the consumables 10 inside the cavity 110 to generate an aerosol. The heater 112 may be provided as one or more curved heating films or tracks extending around the inner wall 104. Alternatively, the heater 112 may be provided as one or more heating films or tracks located at spaced positions around the inner wall.

[0033] The heater 112 is configured to heat the inner wall 104 by conduction, raising the temperature of the air in the cavity 110 to the aerosol generation temperature. The consumable 10 may have a circumference that substantially coincides with the circumference of the cavity 110 so that the consumable 10 comes into contact with the inner wall 104 when the consumable 10 is placed in the cavity 110 by the user. The heater 112 heats the contents of the cavity 110 to a temperature sufficient to generate an aerosol using the tobacco 12 inside the consumable 10. The heater 112 may be configured to heat the contents of the cavity 110 to a temperature lower than the combustion temperature of the tobacco 12, enabling the aerosol generation device 100 to function as a so-called "non-combustion heating" device.

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

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

[0036] In other embodiments, the vacuum insulation material 103 may have other shapes. For example, the vacuum insulation material 103 may have a square or polygonal cross-section, or any other suitable cross-sectional shape. The vacuum insulation material 103 shown in Figures 1 and 3 has a cup shape with one open end and one closed end, but the vacuum insulation material 103 may also have a tubular shape with two open ends. In another embodiment, the outer wall 106 may be directly joined to the inner wall 104 without a connecting flat surface 122a, as shown in Figure 3. The vacuum insulation material 103 may be mechanically attached to the housing 102 by one or more mechanical joints (not shown). The vacuum insulation material 103 may be made of 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 consumables 10 by conduction and can therefore be collectively referred to as the "heater cup". The outer wall 106 and flat surface 122c seal a vacuum 108 around the heater cup and can therefore be referred to as the "outer shell" or "vacuum chamber" of the heater cup. The heater cup and outer shell can be made of different materials. For example, the inner wall 104 and flat surface 122b can be made of metal such as stainless steel, while the outer wall 106 and flat surface 122c can be made of insulating material such as heat-resistant glass. The inner wall 104 and outer wall 106 can be made of any suitable material known in the art. The flat surface 122a can be integrated with the heater cup or outer shell, or it can be provided as a separate component joined to the inner and outer walls 104 and 106.

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

[0039] Here, with reference to Figure 1, an example of the use of the aerosol generating device 100 will be described. During use, the 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 heating to the contents of the cavity 110, including the consumable 10, while the vacuum 108 inside the vacuum insulation material 103 prevents heat leakage from the cavity 110. Thus, the heating device 120 forms an oven that can heat the tobacco 12 inside 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 lower than the tobacco's combustion temperature. When the tobacco 12 is heated, an aerosol is generated inside the cavity 110. The user can inhale the aerosol by drawing in air through the filter 14 and generating an airflow through the consumable 10 that carries the aerosol to the user.

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

[0041] During use, the heater 112 heats the inner wall 104 to a temperature exceeding 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, i.e., "radiant heat," which can be absorbed by the consumable 10 and further heat the consumable 10. However, the outer surface 104b of the inner wall 104 may also undesirably emit radiant heat toward the outer wall 106. This radiation can be absorbed by the outer wall 106 and subsequently lost from the vacuum insulation material 103 by conduction or radiation processes. The present invention minimizes heat loss from the vacuum insulation material 103 by providing a first reflective coating 124 on the outer surface 104b, as shown in Figure 4.

[0042] The first reflective coating 124 can reflect radiation received from the outer surface 104b. In addition, the reflective coating 124 can suppress the emission of radiation from the outer surface 104b. This provides a more efficient insulator for the aerosol generating device 100. Furthermore, the consumable 10 reaches the aerosol generation temperature more quickly because less heat can leak from the cavity 110.

[0043] In the embodiments shown in Figures 1-5, the first reflective coating 124 is provided on all inner walls 104 and flat surfaces 122b (i.e., on all "heater cups"). In other embodiments, the first reflective coating 124 can be provided only on a portion of the inner wall 104, for example, only on the portion of the inner wall 104 and flat surfaces 122b exposed to the vacuum 108. In a further embodiment shown in Figure 6, the first reflective coating 124 can be provided on the heater 112 such that the heater 112 is sealed between the first reflective coating 124 and the inner wall 104. This suppresses emission from the heater 112 toward the inner surface 106a of the outer wall 106, further improving the efficiency of the consumables 10 and shortening the heating time.

[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) toward the cavity 110. This further improves efficiency and reduces the heating time of the consumables 10.

[0045] The second reflective coating 126 can similarly be provided on part or all of the inner wall 106 and the flat surface 122c (i.e., the “outer shell”). The second reflective coating 126 may be made of the same or 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 may 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 containing silver, aluminum, and gold; deposited metal layers such as silver, aluminum, or gold; or glazes such as Heraeus glaze coatings. The metal layers may be provided with an oxide protective layer, although this may not be necessary 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 comprising the corresponding material, may have at least the reflective levels shown in Table 1.

[0047] [Table 1]

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

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

[0050] [Table 2]

[0051] In some embodiments, the reflective coating may be provided on the outer surface 106b of the outer 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, the reflective coating may be provided on the inner surface 104a in addition to the outer surface 104b. In this case, the heater 112 is positioned on the inner surface 104a covering the reflective coating on the inner surface 104a, rather than on the outer surface 104b in the vacuum 108.

Claims

1. Aerosol generating device, An insulating material comprising an inner wall and an outer wall that are separated from each other, A cavity defined within the inner wall that can accept aerosol-forming material, 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 surface of the inner wall, The reflective coating comprises a first layer and a second layer, the first layer and the second layer configured to reflect radiation of different wavelengths. The first layer or the second layer is a layer of reflective paint. Aerosol generating device.

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

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

4. The heater is provided on the outer surface of the inner wall, as described in any one of claims 1 to 3, for the aerosol generating device.

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

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

7. The aerosol generating device according to 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. The aerosol generating device according to any one of claims 1 to 3, wherein the reflective coating comprises a layer of metal foil.

9. The aerosol generating device according to any one of claims 1 to 3, wherein the reflective coating is further provided on the outer surface of the outer wall.

10. An aerosol generating device according to any one of claims 1 to 3, configured to heat an aerosol generating substance comprising tobacco.

11. Aerosol generating device, An insulating material comprising an inner wall and an outer wall that are separated from each other, A cavity defined within the inner wall that can accept aerosol-forming material, A heater positioned to heat the aerosol-forming material when it is received in the cavity, the heater having a reflective coating on its outer wall, comprises: The reflective coating comprises a first layer and a second layer, the first layer and the second layer configured to reflect radiation of different wavelengths. The first layer or the second layer is a layer of reflective paint. Aerosol generating device.

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