Aerosol generating device
The aerosol generating device addresses insulation issues by using an airflow channel with a Venturi effect to reduce heat transfer, enhancing efficiency and comfort through reduced energy use and cooler casing temperatures.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-03-21
- Publication Date
- 2026-03-12
AI Technical Summary
Inadequate insulation of the heating compartment in aerosol-generating devices leads to increased energy consumption and discomfort due to high outer casing temperatures, making the device less efficient and uncomfortable to handle.
An aerosol generating device with an insulating element featuring an airflow channel that creates a Venturi effect, reducing heat transfer to the outer casing by increasing air velocity and decreasing pressure, thereby improving insulation and user comfort.
The device achieves improved efficiency by reducing energy consumption and maintains a cooler outer casing, allowing for more vaping sessions per charge and enhanced user comfort.
Smart Images
Figure 2026508779000001_ABST
Abstract
Description
[Technical Field]
[0001] The present disclosure relates generally to aerosol-generating devices, and more particularly to aerosol-generating devices for heating an aerosol-generating substrate to generate an aerosol for inhalation by a user. [Background technology]
[0002] In recent years, the popularity and use of risk-reducing or risk-modifying devices (also known as vaporizers) has grown rapidly as an alternative to the use of traditional tobacco products. A variety of devices and systems are available that heat or warm, rather than burn, an aerosol-generating substrate to generate an aerosol for inhalation by the user.
[0003] Commonly available risk reduction or risk modification devices are aerosol-generating devices or so-called non-combustion heated devices. This type of device generates an aerosol or vapor by heating an aerosol-generating substrate contained in an aerosol-generating article, such as a heated tobacco stick, in a heating compartment to a temperature typically in the range of 150°C to 300°C. Heating the aerosol-generating substrate to a temperature within this range, without burning or combusting the aerosol-generating substrate, generates a vapor that typically cools and condenses to form an aerosol for inhalation by a user of the device.
[0004] Inadequate insulation of the heating compartment of an aerosol-generating device can lead to reduced efficiency of the device by increasing the energy required to maintain the required operating temperature of the heating compartment. Furthermore, inadequate insulation of the heating compartment of an aerosol-generating device can result in an increase in the temperature of the outer casing of the device, which can result in the device becoming too hot for a user to handle comfortably. Summary of the Invention [Problem to be solved by the invention]
[0005] Therefore, there is a need to provide an aerosol generating device that alleviates these drawbacks. [Means for solving the problem]
[0006] According to a first aspect of the present disclosure, there is provided an aerosol generating device, the aerosol generating device comprising: a heating assembly including a heating compartment positioned to receive an aerosol-generating article; an insulating element disposed between the heating compartment and an outer casing of the aerosol generating device, the insulating element including an air flow channel surrounding the heating compartment, the air flow channel being dimensioned to provide a Venturi effect when air flows through the air flow channel; Includes:
[0007] The Venturi effect is the increase in air velocity and reduction in pressure as the air flows through the airflow channel. The reduction in air pressure in the airflow channel surrounding the heating compartment reduces heat transfer from the heating compartment through the airflow channel to the outer casing of the device, thereby improving the insulation of the heating compartment. Improved insulation of the heating compartment increases the efficiency of the device by reducing the energy required to maintain the required temperature of the heating compartment. Furthermore, improved insulation of the heating compartment reduces the temperature of the outer casing of the device, resulting in a more comfortable device for the user to hold.
[0008] Optionally, the airflow channel comprises: an air inlet portion having an opening through which ambient air can flow into the air flow channel; an air outlet portion having an opening through which ambient air can flow from the air flow channel into the heating compartment; a central portion fluidly connecting the air inlet portion with the air outlet portion, the cross-sectional area of the air flow channel being smallest at the central portion; and Includes.
[0009] In the central portion, the cross-sectional area of the airflow channel is smaller in the central portion than in the air inlet portion, i.e., the airflow channel is constricted, thereby increasing the velocity of the air and decreasing its pressure (the Venturi effect). The Venturi effect is thus caused by a reduction in the pressure of the air as it flows through the constricted central portion of the airflow channel. The airflow channel is therefore sized or shaped such that, in use, there is a pressure drop at the constricted central portion when air flows through the airflow channel.
[0010] A central portion of the air flow channel may extend substantially parallel to the heating compartment. Optionally, the air inlet portion is configured to converge towards the central portion and the air outlet portion is configured to diverge from the central portion.
[0011] The airflow channel may be fluidly connected to a lower portion of a cavity defined by the heating compartment by an opening in the air outlet portion. The airflow channel may be fluidly connected to a cavity defined by the heating compartment having a base by an opening in the air outlet portion that extends through the base into the cavity.
[0012] The opening of the air inlet portion may be substantially annular.
[0013] Optionally, the insulating element includes an inner wall and an outer wall, the air flow channel being defined between the inner wall and the outer wall. Optionally, the outer wall of the insulating element is closed at one end by a base.
[0014] The heating compartment includes a sidewall. Optionally, the inner wall of the insulating element and the sidewall of the heating compartment are separate and distinct. Optionally, the inner wall of the insulating element provides the sidewall of the heating compartment.
[0015] The heating compartment may be sized to receive an aerosol-generating article having a flat rectangular parallelepiped shape. The heating compartment may have a rectangular parallelepiped shape. Optionally, the heating compartment includes a first planar heater and a second planar heater, and the aerosol-generating article is receivable within the heating compartment between the first planar heater and the second planar heater.
[0016] According to a second aspect of the present disclosure, there is provided a method for insulating a heating compartment included in a heating assembly of an aerosol generating device, the method comprising: Drawing air through an airflow channel, the airflow channel being sized to provide a Venturi effect as the air flows through the airflow channel. The air flow channel surrounds the heating compartment, and the air flow channel is contained in a thermal insulating element disposed between the heating compartment and an outer casing of the aerosol generating device. [Brief explanation of the drawings]
[0017] [Figure 1] 1 is a schematic cross-sectional view of an aerosol generating device. [Figure 2] 1 is a schematic perspective view of an exemplary heating assembly of an aerosol generating device shown together with an aerosol-generating article. FIG. [Figure 3] FIG. 3 is a schematic perspective view of an aerosol-generating article suitable for use with the heating assembly of FIG. 2. [Figure 4] FIG. 4 is an end view of the aerosol-generating article of FIG. 3. [Figure 5] 2 is a schematic cross-sectional view of a portion of the aerosol generating device of FIG. 1. DETAILED DESCRIPTION OF THE INVENTION
[0018] Embodiments of the present disclosure will now be described, by way of example only, and with reference to the accompanying drawings, in which:
[0019] 1, there is shown a schematic representation of an aerosol generating device 10 according to the present disclosure. The aerosol generating device 10 is configured for use with an aerosol generating article 16, such that the aerosol generating device 10 and the aerosol generating article 16 together form an aerosol generating system.
[0020] The aerosol-generating device 10 may equally be referred to as a "heated tobacco device," a "non-combustion heated tobacco device," a "device for vaporizing tobacco products," etc., and is to be construed as a device suitable for achieving these effects. The features disclosed herein are equally applicable to devices designed to vaporize any aerosol-generating substrate.
[0021] The aerosol generating device 10 is a handheld, portable device, meaning that the user can hold and support the device in one hand without assistance. The aerosol generating device 10 includes a device housing 46 having a first (or proximal) end 41 and a second (or distal) end 44, and providing an outer casing 48 for the aerosol generating device 10.
[0022] The aerosol generating device 10 includes a controller 50, which may be a printed circuit board assembly (PCBA). The aerosol generating device 10 may include a user interface for controlling the operation of the aerosol generating device 10 via the controller 50.
[0023] The controller 50 may be configured to detect the initiation of use of the aerosol generating device 10, for example, in response to a user input, such as pressing a button to activate the aerosol generating device 10, or in response to a detected airflow through the aerosol generating device 10. As will be understood by those skilled in the art, the airflow through the aerosol generating device 10 indicates an inhalation or "puff" by the user. The aerosol generating device 10 may include a puff detector, such as an airflow sensor (not shown), to detect the airflow through the aerosol generating device 10.
[0024] The controller 50 includes electronic circuitry. The aerosol generating device 10 includes a power source 52, such as a battery.
[0025] The aerosol generating device 10 includes a heating assembly 12 .
[0026] Referring to FIG. 5, the heating assembly 12 further includes a heating compartment 14 (not shown in cross section).
[0027] The heating compartment 14 is positioned to receive an aerosol-generating article 16. The heating compartment 14 defines a cavity 64 for receiving the aerosol-generating article 16. During use, the aerosol-generating article 16 is placed in the cup 64 by a user. After use, the aerosol-generating article 16 can be removed from the cavity 64 by the user and discarded.
[0028] The heating compartment 14 has a first end 54 and a second end 56. The heating compartment 14 includes an opening 58 at the first end 54 for receiving the aerosol-generating article 16. In the illustrated example, the heating compartment 14 includes a sidewall 42.
[0029] The aerosol-generating article 16 includes an aerosol-generating substrate. The aerosol-generating substrate can be any type of solid or semi-solid material. Exemplary types of aerosol-generating solids include powders, granules, pellets, shreds, strands, particles, gels, strips, loose-leaf, cut-leaf, cut-filler, porous materials, foam materials, or sheets. The aerosol-generating substrate can include plant-derived materials, and in particular tobacco. The aerosol-generating substrate can advantageously include reconstituted tobacco. The aerosol-generating substrate can be a tobacco plug.
[0030] The aerosol-forming base may contain an aerosol-forming agent. Examples of aerosol-forming agents include polyhydric alcohols such as glycerin or propylene glycol, and mixtures thereof. Typically, the aerosol-forming base contains about 5% to about 50% aerosol-forming agent by dry weight. In some examples, the aerosol-forming base contains about 10% to about 20% aerosol-forming agent by dry weight, and sometimes about 15% aerosol-forming agent by dry weight.
[0031] Upon heating, the aerosol-forming substrate releases volatile compounds, which may include flavor compounds such as nicotine or tobacco flavorings.
[0032] The shape of the aerosol-generating article 16 corresponds to the shape of the heating compartment 14. In some examples, the aerosol-generating article 16 is generally cylindrical or rod-shaped. In such examples, the aerosol-generating article 16 may be formed in a substantially stick shape and may generally resemble a cigarette, with a tubular region in which the aerosol-generating substrates are arranged in a suitable manner. In other examples, the aerosol-generating article 16 may be a flat-shaped article 88, for example, having a flat rectangular parallelepiped shape, as described below, for example, with reference to Figures 2-4.
[0033] The aerosol-generating article 16 is a disposable and replaceable article, which may, for example, contain tobacco as an aerosol-generating substrate. The aerosol-generating article 16 may be a heated tobacco stick. The aerosol-generating article 16 is a consumable item.
[0034] The aerosol-generating article 16 has a first end 60 (or mouth end) and a second end 62 (see FIG. 1), and includes a filter at the first end 60. The filter functions as a mouthpiece and includes a vent plug (e.g., comprising cellulose acetate fibers).
[0035] The aerosol-generating substrate and filter may be enclosed in a paper wrapper and thus embodied as an aerosol-generating article 16. Some designs may also include one or more vapor collection areas, cooling areas, and other structures.
[0036] To use the aerosol-generating device 10, the user inserts the aerosol-generating article 16 into the cavity of the heating compartment 14 through the opening 58 so that the second end 62 of the aerosol-generating article 16 is positioned at the second end 56 of the heating compartment 14 and the filter 64 at the first end 60 of the aerosol-generating article 16 protrudes from the first end 54 of the heating compartment 14 so that the user can hold it between their lips.
[0037] The heating assembly 12 includes a heater (not shown), i.e., a heating element, positioned to heat the aerosol-generating substrate of the aerosol-generating article 16 received within the cavity 64 of the heating compartment 14 .
[0038] A preferred approach is to use a resistive heating assembly (not shown). Thus, the heating assembly 12 is a resistive heating assembly. In such a case, the heater is a resistive heater (not shown). The resistive heater may surround the aerosol-generating article and transfer heat to the outer surface of the aerosol-generating substrate; for example, the resistive heater may be disposed around the periphery of the heating compartment 14. Alternatively, the resistive heater may be disposed so that it protrudes into the heating compartment 14 from the second end 56 (e.g., a heated blade or pin, etc.) to pierce the aerosol-generating article 16 when the aerosol-generating article 16 is inserted into the cavity 64 of the heating compartment 14 of the aerosol-generating device 10. In use, current from the power source 52 is supplied directly to the resistive heater to generate heat.
[0039] Another approach is to use an induction heating assembly (not shown). In such an example, the heating assembly 12 is an induction heating assembly. The induction heating assembly further includes an induction coil (not shown). The induction coil is configured to be energized to generate an alternating electromagnetic field for inductively heating an inductively heatable susceptor (not shown). Thus, in such an example, the heater is an inductively heatable susceptor.
[0040] The inductively heatable susceptor may surround the aerosol-generating article and transfer heat to the outer surface of the aerosol-generating substrate; for example, the inductively heatable susceptor may be positioned around the periphery of the heating compartment 14. Alternatively, the inductively heatable susceptor may be positioned to protrude into the heating compartment 14 from the second end 56 (e.g., a heating blade or pin, etc.) to pierce the aerosol-generating article 16 when the aerosol-generating article 16 is inserted into the cavity 64 of the heating compartment 14 of the aerosol-generating device 10. In other examples, the inductively heatable susceptor is instead provided within the aerosol-generating substrate during manufacture of the aerosol-generating article 16. In such examples, the aerosol-generating article 16 includes the inductively heatable susceptor.
[0041] The induction coil may be energized by a power supply 52 and a controller 50. The induction coil may comprise a Litz wire or Litz cable, although it will be appreciated that other materials may be used.
[0042] The induction coil may extend around the heating compartment 14. Thus, the induction coil may be annular. The induction coil may be substantially helical in shape. In some examples, the circular cross-section of a helical induction coil may facilitate insertion of the aerosol-generating article 16, and optionally one or more inductively heatable susceptors, into the heating compartment 14 and ensure uniform heating of the aerosol-generating article.
[0043] The inductively heatable susceptor comprises an electrically conductive material, which may include, but is not limited to, one or more of graphite, molybdenum, silicon carbide, niobium, aluminum, iron, nickel, nickel-containing compounds, titanium, mild steel, stainless steel, low-carbon steel, and alloys thereof, such as nickel-chromium or nickel-copper, and composites of metallic materials. In some examples, the inductively heatable susceptor comprises a metal selected from the group consisting of mild steel, stainless steel, and low-carbon stainless steel.
[0044] In use, application of an electromagnetic field in the vicinity of the inductively heatable susceptor causes the inductively heatable susceptor to generate heat due to eddy currents and magnetic hysteresis losses resulting in the conversion of energy from electromagnetic to thermal.
[0045] The induction coil may be arranged, in use, to operate with a varying electromagnetic field having a magnetic flux density of about 20 mT to about 2.0 T (at its highest density point).
[0046] The power supply 52 and electronic circuitry may be configured to operate at high frequencies for the inductively heated steam generation device 10. For example, the power supply 52 and electronic circuitry may be configured to operate at frequencies of about 80 kHz to 500 kHz, optionally about 150 kHz to 250 kHz, and optionally about 200 kHz. The power supply 52 and electronic circuitry may be configured to operate at higher frequencies, for example in the MHz range, if desired.
[0047] In use, heat from the heater (i.e., a resistive heater or an inductively heatable susceptor) is transferred, for example, by conduction, radiation, and convection, to the aerosol-generating article of the aerosol-generating article 16 disposed within the cavity 64 of the heating compartment 14, heating the aerosol-generating article (without burning the aerosol-generating article), thereby generating vapor, which cools and condenses to form an aerosol for inhalation by a user of the aerosol-generating device 10, for example, through a filter.
[0048] Generally speaking, a vapor is a substance that is in the gas phase below its critical temperature, meaning that it can be condensed into a liquid by increasing the pressure without decreasing the temperature. An aerosol, on the other hand, is fine solid particles or liquid droplets suspended in air or another gas. However, it should be noted that the terms "aerosol" and "vapor" may be used interchangeably herein, particularly with respect to the form of inhalable medium generated for inhalation by a user.
[0049] 2 illustrates another exemplary heating assembly 86 of an aerosol generating device 10 according to an example of the present disclosure, shown with an alternative aerosol-generating article 88. The heating assembly 86 is similar to the heating assembly 12 described above, and corresponding components are identified using the same reference numerals.
[0050] 2, the heating assembly 86 includes a first planar heater 66 and a second planar heater 68. In use, the aerosol-generating article 88 is receivable within the heating compartment 14 between the first planar heater 66 and the second planar heater 68. The aerosol-generating article 88 is received within the cavity 64 defined by the heating compartment 14 between the first planar heater 66 and the second planar heater 68.
[0051] In the illustrated example, each planar heater 66, 68 of the heating assembly 86 includes a rectangular ceramic plate with an electric heating element (not shown) embedded therein. The electric heating element has high electrical resistance and generates heat in response to the flow of electric current. The ceramic plate, which is in contact with the aerosol-generating article 88 during use, conducts heat from the heating element and transfers the heat to the aerosol-generating article 88 by conduction. The air within the cavity 64 is also heated. In this manner, the heating assembly 86 and the cavity 64 form a heating oven for the aerosol-generating substrate (e.g., tobacco) within the aerosol-generating article 88.
[0052] Alternatively, the first planar heater 66 and the second planar heater 68 can be other types of heaters, such as non-ceramic metal heating plates.
[0053] FIG. 3 shows a more detailed view of the aerosol-generating article 88 of FIG.
[0054] The aerosol-generating article 88 is a flat-shaped article, for example having a flat rectangular parallelepiped shape extending along an article axis X and having outer dimensions L x W x D. The aerosol-generating article 88 may have any suitable flat shape and / or outer dimensions. The aerosol-generating article 88 may also have any other suitable shape, such as, for example, a stick shape as described above.
[0055] The aerosol-generating article 88 includes a substrate portion 70 and a mouthpiece portion 72 arranged along the article axis X. The substrate portion 70 may be slightly longer than the mouthpiece portion 72, for example. For example, the length L2 of the substrate portion 70 along the article axis X may be substantially equal to 18 mm, and the length L1 of the mouthpiece portion 72 along the article axis X may be substantially equal to 15 mm. The substrate portion 70 defines the abutment end 84 of the aerosol-generating article 88, and the mouthpiece portion 72 defines the mouth end 74 of the aerosol-generating article 88. The substrate portion 70 and the mouthpiece portion 72 may be secured to each other by a wrapper 76 extending around the substrate axis X. The wrapper 76 may be composed of, for example, paper and / or a nonwoven fabric and / or aluminum foil. The wrapper 76 may be porous or air-impermeable and may form a plurality of airflow channels extending inside the aerosol-generating article 88.
[0056] The mouthpiece portion 72 includes a core 78 intended to function as, for example, a cooler to slightly cool the vapor before the user inhales. The core 78 may be made of corrugated cardboard for this purpose. The core 78 may be formed into a stable shape by an extrusion and / or rolling process. Advantageously, the core 78 is positioned inside the mouthpiece portion 72 so as to be in complete contact with the inner surface of the wrapper 76 that separates the mouthpiece portion 72.
[0057] In some examples, the aerosol-generating article 88 may be 2118 or 554 mm 3 The aerosol-generating substrate in the aerosol-generating article 88 may have a total volume of 50 mg. The aerosol-generating substrate in the aerosol-generating article 88 may include, by weight percentage, 50% tobacco, 11.5% propylene glycol (PG), 20% glycerin, 11.0% binder, 4.5% gum, and 3% water. The aerosol-generating substrate in the aerosol-generating article 88 may have a weight of 200 mg. The aerosol-generating substrate may contain 3.07 mg of nicotine.
[0058] Alternatively, the aerosol-generating article may have a weight of 275 mg, contain 4.76 mg of nicotine, 0.9 mg of PG, 44.5 mg of glycerin, and be in the form of an elongated stick.
[0059] The Wrapper 76 is made of 0.13mm thick base paper and 100g / m 2 The wrapper 76 may comprise aluminum foil having a thickness of 0.006 mm. The core 78 may comprise aluminum foil having a thickness of 0.13 mm and a basis weight of 100 g / m 2 The paper may include a paper having a basis weight of
[0060] 4 shows an end view of substrate portion 70. Substrate portion 70 includes vaporizable material 80, i.e., an aerosol-generating substrate, for heating in heating assembly 86. In this example, vaporizable material 80 includes tobacco. Vaporizable material 80 is disposed within wrapper 76 and has a corrugated shape such that a plurality of air channels 82 aligned with substrate axis X are formed within substrate portion 70. Air channels 82 allow air to be drawn through aerosol-generating article 88 during use, so that generated aerosol may be more easily drawn from cavity 64.
[0061] The heating compartment 14 may form a cup shape adapted to receive at least the substrate portion 70 of the aerosol-generating article 88, and optionally at least a portion of the mouthpiece portion 72. The heating compartment 14 is dimensioned to receive the aerosol-generating article 88 having a flat rectangular parallelepiped shape. The heating compartment 14 may form a rectangular parallelepiped shape, similar to the aerosol-generating article 88.
[0062] In this manner, the heating compartment 14 provides a cavity 64 for receiving the aerosol-generating article 88 .
[0063] The heating compartment 14 further includes a first planar heater 66 and a second planar heater 68 disposed within the heating compartment 14 for heating the substrate portion 70 of the aerosol-generating article 88 .
[0064] 5, in the example of the present disclosure, the insulating element 18 is disposed between the heating compartment 14 and the outer casing 48 of the aerosol generating device 10. The insulating element 18 is disposed parallel to the longitudinal axis of the heating compartment 14. The insulating element 18 surrounds the heating compartment 14, i.e., surrounds or encloses the heating compartment 14 on all sides.
[0065] The insulating element 18 includes an air flow channel 20 that surrounds the heating compartment 14. The air flow channel 20 is thus disposed between the heating compartment 14 and an outer casing 48 of the device 10. Thus, in use, heat from the heating compartment 14 must be transferred through the air flow channel 20 between the inner wall 36 and the outer wall 38 to reach the outer casing 48.
[0066] The air flow channel 20 is sized to provide a Venturi effect when air flows through the air flow channel 20. The air flow channel 20 is sized to utilize the Venturi effect. The air flow channel 20 is sized so that, in use, a Venturi effect is created when air flows through the air flow channel 20. The air flow channel is configured to utilize or provide the Venturi effect. The Venturi effect is created within the air flow channel 20 during inhalation of the aerosol-generating article 16.
[0067] Thus, a heating, non-burning device 10 is provided having an air flow channel 20 sized to provide a venturi effect as air flows therethrough. The air flow channel 20 provides an air flow passageway.
[0068] The Venturi effect is the increase in velocity and reduction in pressure (i.e., decrease) of air (i.e., fluid) as it flows through the airflow channel 20. The reduction in air pressure within the airflow channel 20 surrounding the heating compartment 14 reduces heat transfer from the heating compartment 14 through the airflow channel 20 to the outer casing 48 of the device 10, thereby improving the insulation of the heating compartment 14. Improved insulation of the heating compartment 14 increases the efficiency of the device 10 by reducing the energy required to maintain the required temperature of the heating compartment 14. Furthermore, improved insulation of the heating compartment 14 reduces the temperature of the device's outer casing 48, resulting in a more comfortable holding of the device 10 by a user. Thus, a lower-cost device 10 may provide more vaping sessions per charge and have a cooler outer casing 48.
[0069] The configuration of the airflow channel 20 varies to reduce the air pressure along a portion of the length of the airflow channel 20. This Venturi effect therefore drives ambient air along the airflow channel 20 to provide a cooling effect to the outer casing 48.
[0070] Thus, the insulating element 18 provides a venturi cooling chamber 18. The airflow channel 20 can be thought of as a venturi tube.
[0071] The air flow channel 20 includes an air inlet portion 22 having an opening 24 through which ambient air can flow, or be drawn, into the air flow channel 20. In some examples, the opening 24 in the air inlet portion 22 is substantially annular, or ring-shaped. The ring-shaped opening 24 is at the top of the insulation element 18 when in use.
[0072] The air flow channel 20 further includes an air outlet portion 26 having an opening 28 through which ambient air can flow from the air flow channel 20 into the cavity 64 defined by the heating compartment 14 to facilitate vaporization of the aerosol-forming substrate contained in the aerosol-generating article 16. Thus, vaporization of the aerosol-forming substrate is facilitated by the addition of air from the ambient environment.
[0073] The air flow channel 20 further includes a central portion 30 that fluidly connects the air inlet portion 22 with the air outlet portion 26. In the illustrated example, the central portion 30 of the air flow channel 20 extends parallel to the heating compartment 14.
[0074] The cross-sectional area of the airflow channel 20 is smallest at the central portion 30. Accordingly, the cross-sectional area of the airflow channel increases, or becomes larger, at the air inlet portion 22 and the air outlet portion 26. Thus, the central portion 30 defines a constricting airflow passage. Thus, the configuration of the airflow channel 20 changes to reduce air pressure along the length of the central portion 30 of the airflow channel 20. This Venturi effect therefore drives ambient air along the airflow channel 20 from the air inlet portion 22 to the air outlet portion 26 to provide a cooling effect to the outer casing 48.
[0075] The air inlet portion 22 is configured to converge towards the central portion 30. The air outlet portion 26 is configured to diverge from the central portion 30. The air inlet portion 22 is located upstream of the central portion 30, and the air outlet portion 26 is located downstream of the central portion 30.
[0076] 5, at (1), ambient air enters air inlet portion 22 through opening 24 at a relatively high pressure and low velocity (i.e., flow rate) as a user draws air over aerosol-generating article 16. Thus, the user draws air through airflow channel 20 by inhaling.
[0077] In (2), at the central portion 30, the cross-sectional area of the air flow channel 20 is smaller at the central portion 30 than at the air inlet portion 22, i.e., the air flow channel is constricted, thereby increasing the velocity of the air and decreasing its pressure (the Venturi effect). The air flow channel 20 has a constricted space at the central portion 30. The Venturi effect is therefore caused by a reduction (i.e., drop) in the pressure of the air as it flows through the constricted central portion 30 of the air flow channel 20. Thus, the air flow channel 20 is sized or shaped such that, in use, a pressure drop exists at the constricted central portion 30 when air flows through the air flow channel 20. Thus, the low-pressure air is utilized to insulate the heating compartment 14 (i.e., the oven).
[0078] At (3), a relatively high pressure and low velocity of air is restored at the air outlet portion 26 because the cross-sectional area of the air outlet portion 26 is larger than that of the central portion 30. Air is drawn from the air outlet portion 26 through the opening 28 into the cavity 64 defined by the heating compartment 14 and through the aerosol-generating article 16 received therein to promote vaporization of the aerosol-generating substrate contained in the aerosol-generating article 16 for inhalation by a user of the aerosol-generating device 10.
[0079] In some examples, the air flow channel 20 is fluidly connected to a lower portion (not visible in the drawings) of the cavity 64 defined by the heating compartment 14 by the opening 28 in the air outlet portion 26. In the illustrated example, the side wall 42 of the heating compartment 14 is closed at one end, i.e., the second end 56, by the base 34. The opening 28 in the air outlet portion 26 extends through the base 34 to fluidly connect the air flow channel 20 with the cavity 64 defined by the heating compartment 14. The base 34 provides the bottom of the heating compartment 14 and thus provides the inner bottom (i.e., lowermost) surface of the cavity 64.
[0080] In the illustrated example, the air flow channel 20 is defined between an inner wall 36 and an outer wall 38. The air flow channel 20 is therefore defined by the two walls 36, 38 that are exterior to the heating compartment 14. In use, air is pulled through between the two side walls 36, 38 by a user drawing on the aerosol-generating article 16.
[0081] The outer wall 38 of the insulating element 18 is closed at one end by a base 40 .
[0082] In the illustrated example, the side walls 36, 38 are bent to supply air to the bottom of the aerosol-generating article 16 received within the cavity 64 defined by the heating compartment 14 to extract vapor from the aerosol-generating article (e.g., a cigarette).
[0083] The cross-sectional area of the central portion 30 of the air flow channel 20 between two side walls 36, 38 extending parallel to the aerosol-generating article 16 (i.e., the tobacco stick) is smaller than the cross-sectional areas of the air inlet portion 22 and the air outlet portion 26 to ensure that a low-pressure zone is created during inhalation. This low-pressure zone serves to reduce heat transfer outside the heating compartment 14 and to insulate the tobacco stick 16. In addition, between puffs, the generated hot air is then drawn into the aerosol-generating substrate (e.g., tobacco), which serves to raise the temperature of the stick 16. When ambient air replaces it, this reduces the extracted heat transfer.
[0084] In the illustrated example, the inner wall 36 of the insulating element 18 and the side wall 42 of the heating compartment 14 are separate and distinct. In such an example, the insulating element 18 and the heating compartment 14 have separate side walls 36, 42. In such an example, a heater may be wrapped around a metal cup defining the heating compartment 14 to hold the aerosol-generating article 16 with the separate outer insulating element 18.
[0085] In another example, not shown, the inner wall 36 of the insulating element 18 provides the side wall 42 of the heating compartment 14. In such an example, the insulating element 18 and the heating compartment 14 share the side wall 36, 42. In such an example, the heater may be printed on the inner wall 36 of the insulating element 18, and the insulating element 18 also provides a metal cup defining the heating compartment 14 for holding the aerosol-generating article 16.
[0086] The figure also illustrates a method of insulating the heating compartment 14 included in the heating assembly 12, 86 of the aerosol generation device 10, 88. The method involves drawing air through an air flow channel 20 that is sized to provide a Venturi effect as the air flows through the air flow channel 20. The air flow channel 20 surrounds the heating compartment 14. The air flow channel 20 is contained in an insulating element 18 that is positioned between the heating compartment 14 and the outer casing 48 of the aerosol generation device 10.
[0087] The figures also illustrate a method of manufacturing an aerosol generating device 10 according to examples of the present disclosure. The figures also illustrate a method of providing an aerosol generating system according to examples of the present disclosure.
[0088] While exemplary embodiments have been described in the preceding paragraphs, it should of course be understood that various modifications to those embodiments may be made without departing from the scope of the appended claims, and therefore, the breadth and scope of the claims should not be limited to the above-described exemplary embodiments.
[0089] Any combination of the above-described features in all possible variations thereof is encompassed by the present disclosure unless otherwise indicated herein or otherwise clearly contradicted by context.
[0090] Unless the context clearly requires otherwise, throughout this specification and claims, the words "comprises," "including," and the like are to be construed in an inclusive, i.e., "including but not limited to," sense, as opposed to an exclusive or exhaustive sense.
Claims
1. An aerosol generating device (10), comprising: a heating assembly (12, 86) including a heating compartment (14) positioned to receive an aerosol-generating article (16, 88); an insulating element (18) disposed between the heating compartment (14) and an outer casing (48) of the aerosol generating device (10), the insulating element (18) including an air flow channel (20) surrounding the heating compartment (14), the air flow channel (20) being dimensioned to provide a Venturi effect when air flows through the air flow channel (20); An aerosol generating device (10) comprising:
2. The air flow channel (20) an air inlet portion (22) having an opening (24) through which ambient air can flow into said air flow channel (20); an air outlet portion (26) having an opening (28) through which ambient air can flow from the air flow channel (20) into the heating compartment (14); a central portion (30) fluidly connecting the air inlet portion (22) with the air outlet portion (26), the cross-sectional area of the air flow channel (20) being smallest at the central portion (30); The aerosol generating device (10) of claim 1, comprising:
3. 3. The aerosol generating device according to claim 2, wherein the central portion (30) of the air flow channel (20) extends substantially parallel to the heating compartment (14).
4. 4. The aerosol generating device of claim 2 or 3, wherein the air inlet portion (22) is configured to converge toward the central portion (30), and the air outlet portion (26) is configured to diverge from the central portion (30).
5. An aerosol generating device as described in any one of claims 2 to 4, wherein the air flow channel (20) is fluidly connected to a lower part of a cavity (64) defined by the heating compartment (14) by the opening (28) of the air outlet portion (26).
6. 5. The aerosol generating device of claim 2, wherein the air flow channel (20) is fluidly connected to a cavity (64) defined by the heating compartment (14) having a base (34) by the opening (28) of the air outlet portion (26) extending through the base (34) into the cavity (64).
7. 7. The aerosol generating device according to claim 2, wherein the opening (24) of the air inlet portion (22) is substantially annular.
8. 8. The aerosol generating device according to claim 1, wherein the insulating element (18) comprises an inner wall (36) and an outer wall (38), and the air flow channel (20) is defined between the inner wall (36) and the outer wall (38).
9. 9. The aerosol generating device of claim 8, wherein the outer wall (38) of the insulating element (18) is closed at one end by a base (40).
10. 10. The aerosol generating device of claim 8 or 9, wherein the heating compartment (14) includes a side wall (42), and the inner wall (36) of the insulating element (18) and the side wall (42) of the heating compartment (14) are separate and different.
11. 10. The aerosol generating device of claim 8 or 9, wherein the heating compartment (14) includes a side wall (42), and the inner wall (36) of the insulating element (18) provides the side wall (42) of the heating compartment (14).
12. 12. The aerosol generating device according to any one of claims 1 to 11, wherein the heating compartment (14) is dimensioned to receive an aerosol-generating article (88) having a flat rectangular parallelepiped shape.
13. 13. The aerosol generating device according to claim 12, wherein the heating compartment (14) has a rectangular parallelepiped shape.
14. 14. The aerosol generating device of claim 12 or 13, wherein the heating compartment (14) includes a first planar heater (66) and a second planar heater (68), and the aerosol-generating article (88) is receivable within the heating compartment (14) between the first planar heater (66) and the second planar heater (68).
15. A method for insulating a heating compartment (14) included in a heating assembly (12, 86) of an aerosol generating device (10), comprising: Drawing air through an air flow channel (20) sized to provide a venturi effect as air flows through said air flow channel (20). wherein the air flow channel (20) surrounds the heating compartment (14), and the air flow channel (20) is contained in an insulating element (18) arranged between the heating compartment (14) and an outer casing (48) of the aerosol generating device (10).