Aerosol generator with restricted airflow path

Abstract

1. An aerosol generating device (100), comprising: an air inlet (116); a cavity for accommodating at least a portion of an aerosol-generating article; and an airflow channel (118) defining an airflow path extending between the air inlet and the cavity, the airflow channel comprising a first airflow channel portion (118a) and a second airflow channel portion (118b), wherein a cross-sectional area of ​​the airflow path in the first airflow channel portion is smaller than a cross-sectional area of ​​the airflow path in the second airflow channel portion, and wherein the aerosol generating device is configured to restrict airflow in the first airflow channel portion.

Description

Technical Field

[0001] The present disclosure relates to an aerosol generating device. Specifically, the present disclosure relates to, but is not exclusive to, a handheld electrically operated aerosol generating device for heating an aerosol forming substrate to generate an aerosol and delivering the aerosol to a user. The present disclosure also relates to an aerosol generating system comprising an aerosol generating device and an aerosol generating article.

Background Art

[0002] Aerosol generating devices that heat an aerosol forming substrate to produce an aerosol without burning the aerosol forming substrate are known in the art and are often referred to as heat-not-burn devices. The aerosol forming substrate is typically provided within an aerosol generating article together with other components such as a filter. The aerosol generating article may have a rod shape for insertion of the aerosol generating article into a cavity of the aerosol generating device. The heating element is typically disposed within or around the cavity to heat the aerosol forming substrate when the aerosol generating article is inserted into the cavity of the aerosol generating device. In use, the heating element heats the aerosol generating article inserted into the cavity of the aerosol generating device to generate an aerosol from the aerosol forming substrate. In many such devices, the user inhales the aerosol from the end of the aerosol generating article protruding from the aerosol generating device.

[0003] For a user, the "draw resistance" (RTD) is an important quality parameter of the aerosol generating article and is a measure of the pressure drop when passing through the aerosol generating article. In other words, it is a measure of how much suction force the user needs to apply to inhale air and the generated aerosol through the aerosol generating article. For aerosol generating articles for heat-not-burn devices, it is desirable for the RTD to reproduce the draw of a conventional cigarette. The acceptable RTD for the comfort of a user of a conventional cigarette is typically in the range of 60 to 100 millimeters of water column (mmWg).

[0004] There are several ways to customize the RTD of an aerosol generating article. For example, the RTD can be adjusted by changing the density or size of the tobacco components within the tobacco plug. Alternatively or additionally, elements that restrict airflow and thus cause a pressure drop can be placed at the proximal or distal end of the consumable, such as a filter. Furthermore, the tolerance of the RTD parameters for the various components of the aerosol generating article is particularly important for rods made from natural materials, such as tobacco rods made only from finely cut and slightly compressed tobacco leaves. For example, the RTD variation of a tobacco plug with a length of 10 mm can vary from 10 mmWg to 25 mmWg. This variation affects the performance of the aerosol generating article and the aerosol delivered to the user. Moreover, once the components of an aerosol generating article, such as a filter plug or tobacco plug, are manufactured, there is little possibility of further adjusting the RTD. Therefore, users may need to produce different suction forces for different aerosol generating articles, which can negatively impact the user experience.

[0005] As used herein, the terms “distal,” “upstream,” “proximal,” and “downstream” describe the relative positions of components or parts of components of an aerosol generator and an aerosol generating article. The aerosol generating articles and devices according to this disclosure have a proximal end through which aerosol exits the aerosol generating article or device for delivery to a user during use, and a distal end on the opposite side. During use, the user inhales the proximal end of the aerosol generating article. The terms upstream and downstream refer to the direction of movement of aerosol or air through the aerosol generating article or aerosol generating device when the user inhales the proximal end of the aerosol generating article. The proximal end of the aerosol generating article is downstream of the distal end of the aerosol generating article. The proximal end of the aerosol generating article may also be referred to as the downstream end of the aerosol generating article, and the distal end of the aerosol generating article may also be referred to as the upstream end of the aerosol generating article.

[0006] To provide a satisfying and consistent user experience, it is desirable to provide an aerosol generator that is less dependent on the characteristics of the aerosol-generating article. In particular, it is desirable to provide an aerosol generator that results in a more stable and repeatable RTD (Ready-to-Drink). [Overview of the project]

[0007] An aerosol generator is provided according to embodiments of the present disclosure. The aerosol generator may include an air intake. The aerosol generator may include a cavity for receiving an aerosol generating article. The aerosol generator may include an airflow channel that defines an airflow path extending between the air intake and the cavity. The airflow channel may include a first airflow channel section and a second airflow channel section. The cross-sectional area of ​​the airflow path in the first airflow channel section may be smaller than the cross-sectional area of ​​the airflow path in the second airflow channel section. The aerosol generator may be configured to restrict the airflow in the first airflow channel section.

[0008] According to embodiments of the present disclosure, an aerosol generator is provided comprising an air intake, a cavity for housing an aerosol generating article, and an airflow channel defining an airflow path extending between the air intake and the cavity. The airflow channel comprises a first airflow channel section and a second airflow channel section. The cross-sectional area of ​​the airflow path in the first airflow channel section is smaller than the cross-sectional area of ​​the airflow path in the second airflow channel section, and the aerosol generator is configured to restrict the airflow within the first airflow channel section.

[0009] Advantageously, in the above embodiment, a large RTD is generated not only within the aerosol generating article but also within the aerosol generator. This means that the aerosol generator provides the required RTD with less dependence on the characteristics of the aerosol generating article. The RTD is generated by providing a first airflow channel section having an airflow path with a reduced cross-sectional area compared to the rest of the airflow channel. The reduced cross-sectional area restricts the airflow. Since the dimensions of the airflow channel of the aerosol generator are fixed and the same with each use, the RTD value is relatively constant. Therefore, substantially the same suction force from the user is required each time the user blows during the experience. Furthermore, the RTD is repeatable and stable over the lifespan of the aerosol generator and during the use of a single aerosol generating article.

[0010] The draw resistance when passing through the airflow channel may be greater than 50 millimeters of water column. The draw resistance when passing through the airflow channel may be 20 to 100 millimeters of water column. The draw resistance when passing through the airflow channel may be 25 to 95 millimeters of water column. The draw resistance when passing through the airflow channel may be 30 to 90 millimeters of water column. The draw resistance when passing through the airflow channel may be 35 to 85 millimeters of water column. The draw resistance when passing through the airflow channel may be 40 to 80 millimeters of water column. The draw resistance when passing through the airflow channel may be 45 to 75 millimeters of water column. The draw resistance when passing through the airflow channel may be 50 to 70 millimeters of water column.

[0011] Unless otherwise specified, the draw resistance (RTD) of an aerosol generator, aerosol generating article, or any component thereof shall be measured in accordance with ISO 6565-2015. RTD refers to the pressure required to pass air through the entire length of the component. The terms “pressure drop” or “draw resistance” of a component or article may also refer to “resistance to draw.” These terms generally refer to the fact that the measurement in accordance with ISO 6565-2015 is successfully performed under a test of a volumetric flow rate of approximately 17.5 milliliters per second at the output or downstream end of the component being measured, at a temperature of approximately 22 degrees Celsius, a pressure of approximately 101 kPa (approximately 760 Torr), and a relative humidity of approximately 60%.

[0012] The end of the first airflow channel may be positioned at the air intake to restrict the airflow path at the air intake.

[0013] The ratio of the cross-sectional area of ​​the airflow path in the second airflow channel to the cross-sectional area of ​​the airflow path in the first airflow channel may be 10:1 to 100:1, preferably 10:1 to 20:1. These ratios have been shown to be particularly effective in producing a desirable RTD.

[0014] The airflow channel may include a tubular casing. The inner surface of the tubular casing may define the airflow path.

[0015] The first airflow channel of the tubular casing may have an internal width or diameter of 0.5 mm to 2 mm, preferably 0.75 mm to 1.5 mm. These dimensions have been found to be particularly effective in producing the desired RTD.

[0016] The second airflow channel portion of the tubular casing may have an internal width or diameter of 4 to 6 millimeters.

[0017] The ratio of the length of the second airflow channel to the length of the first airflow channel may be 5:1 to 1:1, preferably 4:1 to 2:1. These ratios have been shown to be particularly effective in producing a desirable RTD.

[0018] The first airflow channel section has a length of 5 mm to 25 mm, preferably 12 mm to 18 mm, more preferably 14 mm to 16 mm, and even more preferably about 15 mm. These dimensions have been found to be particularly effective in producing the desired RTD.

[0019] The first airflow channel may be tapered. The first airflow channel may have an outlet width or diameter (at the downstream end of the first airflow channel) that is smaller than the inlet width or diameter (at the upstream end of the first airflow channel). The outlet width or diameter of the first airflow channel may be 5 to 15 percent smaller than the inlet width of the first airflow channel, or preferably about 10 percent smaller. The width or diameter of the first airflow channel may decrease linearly between the upstream and downstream ends of the first airflow channel. The width or diameter of the first airflow channel may decrease non-linearly between the upstream and downstream ends of the first airflow channel.

[0020] The first airflow channel may have an inlet width or diameter of 1 mm to 2 mm, preferably 1 mm to 1.5 mm, and more preferably about 1.3 mm. The first airflow channel may have an outlet width or diameter of 0.75 mm to 1.5 mm, preferably 1 mm to 1.25 mm, and more preferably about 1.2 mm.

[0021] The first airflow channel may have an outlet width or diameter (at the downstream end of the first airflow channel) that is larger than the inlet width or diameter (at the upstream end of the first airflow channel). The outlet width or diameter of the first airflow channel may be 5 to 15 percent larger than the inlet width of the first airflow channel, or preferably about 10 percent larger. The width or diameter of the first airflow channel may increase linearly between the upstream and downstream ends of the first airflow channel. The width or diameter of the first airflow channel may increase non-linearly between the upstream and downstream ends of the first airflow channel.

[0022] The first airflow channel may have an outlet width or diameter of 1 mm to 2 mm, preferably 1 mm to 1.5 mm, and more preferably about 1.3 mm. The first airflow channel may have an inlet width or diameter of 0.75 mm to 1.5 mm, preferably 1 mm to 1.25 mm, and more preferably about 1.2 mm.

[0023] The first and second airflow channels may be integrally formed within the tubular casing. This helps reduce the number of components and simplify the manufacturing of the aerosol generator.

[0024] The first airflow channel section may be equipped with a removable plug. The removable plug may be configured to connect to a second airflow channel section. The removable plug may have a through-hole extending between its opposing ends, defining an airflow path through the plug. Advantageously, in this configuration, the removable plug provides an RTD. Different removable plugs having through-holes of different cross-sectional areas may be used to allow the user to configure the aerosol generator to have a preferred RTD. The removable plug may have an RTD of about 20 millimeters of water column, or about 30 millimeters of water column, or about 40 millimeters of water column, or about 50 millimeters of water column, or about 60 millimeters of water column.

[0025] The aerosol generator may further include a heater for heating the aerosol-generating article inside the cavity.

[0026] A heater may comprise one or more electric heating elements. These electric heating elements may include electrical resistive materials. Suitable electrical resistive materials include, but are not limited to, semiconductors such as doped ceramics, "conductive" ceramics (e.g., molybdenum disilide), carbon, graphite, metals, alloys, and composite materials made of ceramic and metallic materials. Such composite materials may include doped or undoped ceramics. A suitable example of a doped ceramic is doped silicon carbide. Suitable examples of metals include titanium, zirconium, tantalum, and platinum group metals. Examples of suitable metal alloys include stainless steel, nickel-containing alloys, cobalt-containing alloys, chromium-containing alloys, aluminum-containing alloys, titanium-containing alloys, zirconium-containing alloys, hafnium-containing alloys, niobium-containing alloys, molybdenum-containing alloys, tantalum-containing alloys, tungsten-containing alloys, tin-containing alloys, gallium-containing alloys, manganese-containing alloys, gold-containing alloys, and iron-containing alloys, as well as nickel, iron, cobalt, stainless steel-based superalloys, Timetal®, Kanthal®, and other iron-chromium-aluminum alloys, and iron-manganese-aluminum alloys. In composite materials, the electrically resistive material may be embedded in an insulating material, sealed in an insulating material, or coated with an insulating material, depending on the required energy transfer dynamics and external physicochemical properties. Alternatively, the electric heater may include one or more infrared heating elements, photonic sources, or induction heating elements.

[0027] One or more heating elements may be formed using a metal or metal alloy having a clear relationship between temperature and resistivity. Heating elements formed in this manner may be used both for heating the heating element and for monitoring the heating element's temperature during operation.

[0028] The heating element may be disposed within or on a rigid carrier material or substrate. The heating element may be formed as a track on a suitable insulating material such as ceramic or glass. The heating element may be sandwiched between two insulating materials.

[0029] The heater may include an internal heater, or an external heater, or both an internal heater and an external heater, where "internal" and "external" refer to the position relative to the aerosol-forming substrate.

[0030] The internal heater may take any suitable form. For example, the internal heater may take the form of a heating blade. Alternatively, the internal heater may take the form of a casing or substrate having different conductive portions or an electrically resistive metal tube. Alternatively, the internal heater may be one or more heating needles or rods extending through the center of the aerosol-forming substrate. Other alternatives include heating wires or filaments such as Ni-Cr (nickel-chromium), platinum, gold, silver, tungsten, or alloy wires or heating plates.

[0031] The external heater may take any suitable form. For example, the external heater may take the form of one or more flexible heating foils on a dielectric substrate such as polyimide. The flexible heating foil can be shaped to conform to the periphery of a cavity for containing the aerosol-generating article. Alternatively, the external heater may take the form of a heating coil, one or more metal grids, a flexible printed circuit board, a molded circuit component (MID), a ceramic heater, a flexible carbon fiber heater, or may be formed using a coating technique such as plasma deposition on a substrate of a suitable shape.

[0032] The heater may be a tubular heater disposed to receive an aerosol-forming substrate or aerosol-generating article within the internal space of the tube. The tubular heater may comprise a tubular support or substrate having a heating element disposed on or within the support or substrate. The heating element may be disposed on the inner surface of the tube or on the outer surface of the tube. In one embodiment, the heater may include an aluminum oxide ceramic tube having a Kanthal® heating element surrounding the outer cylindrical surface of the tube.

[0033] The aerosol generator may further include a power source or supply for powering the internal and external heaters. The power source may be any suitable power source, such as a DC voltage source. In one embodiment, the power source is a lithium-ion battery. Alternatively, the power source may be a nickel-metal hydride battery, a nickel-cadmium battery, or a lithium-based battery, such as a lithium-cobalt, lithium iron phosphate, or lithium polymer battery.

[0034] The aerosol generator is preferably a handheld aerosol generator that is comfortable for the user to hold between the fingers of one hand.

[0035] The aerosol generator may further include a control circuit configured to control the supply of power to the heater assembly. The control circuit may include a microprocessor. The microprocessor may be a programmable microprocessor, a microcontroller, an application-specific integrated circuit (ASIC), or other electronic circuit capable of providing control. The control circuit may include further electronic components. For example, in some embodiments, the control circuit may include a sensor element, a switch element, or a display element. Power may be supplied to the heater assembly continuously after the device is started, or intermittently (e.g., with each smoke extraction). Power may be supplied to the heater assembly in the form of current pulses, for example, by pulse width modulation (PWM).

[0036] The aerosol generator may include a housing. The housing may have a cavity for housing an aerosol-forming substrate or an aerosol-generating article. The housing may include a heater, a power supply, and a control circuit. The housing may include an air intake. The housing may contain any suitable material or combination of materials. Examples of suitable materials include metals, alloys, plastics, or composite materials containing one or more of these materials, or thermoplastic resins suitable for food or pharmaceutical applications, such as polypropylene, polyetheretherketone (PEEK), and polyethylene. The material is preferably lightweight and not brittle.

[0037] Another embodiment of the present disclosure provides an aerosol generating system comprising any of the aerosol generating devices described above. The aerosol generating system may comprise an aerosol generating article. The aerosol generating article may include an aerosol forming substrate.

[0038] According to one embodiment of the present disclosure, an aerosol generating system is provided comprising any of the above-described aerosol generating devices and an aerosol generating article. The aerosol generating article comprises an aerosol forming substrate.

[0039] As used herein, the term “aerosol-generating article” refers to an article comprising an aerosol-forming substrate that releases volatile compounds capable of forming aerosols when heated within an aerosol generator. The aerosol-generating article is separated from the aerosol generator and is also configured to be combined with the aerosol generator for heating the aerosol-generating article.

[0040] The aerosol-generating article may be substantially cylindrical in shape. The aerosol-generating article may be substantially elongated. The aerosol-forming substrate may be substantially cylindrical in shape. The aerosol-forming substrate may be substantially elongated.

[0041] The aerosol generating article may have an overall length of approximately 30 mm to approximately 100 mm. The aerosol generating article may have an outer diameter of approximately 5 mm to approximately 12 mm. The aerosol forming substrate may have a length of approximately 10 mm to approximately 18 mm. Furthermore, the diameter of the aerosol forming substrate may be approximately 5 mm to approximately 12 mm. The aerosol generating article may be equipped with a filter plug. The filter plug may be located at the downstream end of the aerosol generating article. The filter plug may be a cellulose acetate filter plug. In one embodiment, the filter plug is approximately 7 mm long, but may have a length of approximately 5 mm to approximately 12 mm.

[0042] In one embodiment, the aerosol generating article may have a total length of approximately 45 mm. The aerosol generating article may have an outer diameter of approximately 7.3 mm, or it may have an outer diameter of approximately 7.0 mm to approximately 7.4 mm. Furthermore, the aerosol forming substrate may have a length of approximately 12 mm. Alternatively, the aerosol forming substrate may have a length of approximately 16 mm. The aerosol generating article may be provided with an outer paper wrapper. Furthermore, the aerosol generating article may be provided with a separation section between the aerosol forming substrate and the filter plug. The separation section may be approximately 21 mm or approximately 26 mm, or it may be in the range of approximately 5 mm to approximately 28 mm. Separation may be provided by a hollow tube. The hollow tube may be made from cardboard or cellulose acetate.

[0043] The aerosol-forming substrate may be a solid aerosol-forming substrate. Alternatively, the aerosol-forming substrate may comprise both solid and liquid components. The aerosol-forming substrate may comprise a tobacco-containing material that contains volatile tobacco-flavored compounds released from the substrate upon heating. Alternatively, the aerosol-forming substrate may comprise a non-tobacco material. The aerosol-forming substrate may further comprise an aerosol-forming body. Examples of suitable aerosol-forming bodies include glycerin and propylene glycol.

[0044] If the aerosol-forming substrate is a solid aerosol-forming substrate, it may contain one or more of the following: herb leaves, tobacco leaves, tobacco vein fragments, reconstituted tobacco, homogenized tobacco, extruded tobacco, and puffed tobacco, and may be in the form of, for example, powder, granules, pellets, fragments, spaghetti, slivers, or sheets. The solid aerosol-forming substrate may be in loose form or may be provided in a suitable container or cartridge. Optionally, the solid aerosol-forming substrate may contain additional tobacco or non-tobacco volatile flavor compounds that are released upon heating of the substrate. The solid aerosol-forming substrate may also contain, for example, capsules containing additional tobacco or non-tobacco volatile flavor compounds, which may melt during heating of the solid aerosol-forming substrate.

[0045] As used herein, “homogenized tobacco” refers to a material formed by agglomerating particulate tobacco. Homogenized tobacco may be in the form of a sheet. Homogenized tobacco material may have an aerosol-forming content greater than 5 percent by dry weight. Alternatively, homogenized tobacco material may have an aerosol-forming content of 5 to 30 percent by weight by dry weight. Homogenized tobacco material sheets may be formed by agglomerating particulate tobacco obtained by crushing or otherwise finely grinding one or both of the leaf blades and / or stems of tobacco leaves. Alternatively, or additionally, homogenized tobacco material sheets may include one or more of the following: tobacco dust, tobacco fines, and other particulate tobacco by-products formed during tobacco processing, handling, and shipping. The homogenized tobacco material sheet may contain one or more inherent binders (i.e., endogenous tobacco binders), one or more exogenous binders (i.e., exogenous tobacco binders), or a combination thereof, to help aggregate particulate tobacco. Alternatively, or additionally, the homogenized tobacco material sheet may contain other additives, including but not limited to tobacco and non-tobacco fibers, aerosol formizers, wetting agents, plasticizers, flavoring agents, fillers, aqueous and non-aqueous solvents, and combinations thereof.

[0046] In a particularly preferred embodiment, the aerosol-forming substrate comprises an aggregate of crimped sheets of homogenized tobacco material. As used herein, the term “crimped sheet” means a sheet having a plurality of substantially parallel ridges or undulations. When the aerosol-generating article is assembled, it is preferable that the substantially parallel ridges or undulations extend along or parallel to the longitudinal axis of the aerosol-generating article. This is advantageous as it facilitates the assembly of crimped sheets of homogenized tobacco material to form the aerosol-forming substrate. However, naturally, the crimped sheets of homogenized tobacco material to be included in the aerosol-generating article may, in an alternative or additional manner, have a plurality of substantially parallel ridges or undulations that are arranged at acute or obtuse angles with respect to the longitudinal axis of the aerosol-generating article when the aerosol-generating article is assembled. In a particular embodiment, the aerosol-forming substrate may comprise an aggregate of sheets of homogenized tobacco material that are substantially uniformly textured across substantially its entire surface. For example, the aerosol-forming substrate may include an aggregate of crumpled sheets of homogenized tobacco material, each containing a plurality of substantially parallel ridges or undulations substantially evenly spaced across the width of the sheet.

[0047] Optionally, the solid aerosol-forming substrate may be provided on or embedded within a thermally stable carrier. The carrier may take the form of a powder, granules, pellets, fragments, spaghetti, strips, or sheets. Alternatively, the carrier may be a tubular carrier having a thin layer of solid substrate deposited on its inner surface, its outer surface, or both its inner and outer surfaces. Such tubular carriers may be formed from, for example, paper or paper-like material, nonwoven carbon fiber mat, low-mass coarse mesh metal screen, or perforated metal foil, or any other thermally stable polymer matrix.

[0048] The solid aerosol-forming substrate may be deposited on the surface of a carrier, for example, in the form of a sheet, foam, gel, or slurry. The solid aerosol-forming substrate may be deposited over the entire surface of the carrier, or alternatively, in a pattern to provide non-uniform flavor delivery during use.

[0049] Although the above refers to a solid aerosol-forming substrate, it will be apparent to those skilled in the art that other forms of aerosol-forming substrates may be used in other embodiments. For example, the aerosol-forming substrate may be a liquid aerosol-forming substrate. If a liquid aerosol-forming substrate is provided, the aerosol generator preferably includes means for holding the liquid. For example, the liquid aerosol-forming substrate may be held in a container or liquid storage section. Alternatively, or additionally, the liquid aerosol-forming substrate may be absorbed into a porous carrier material. The porous carrier material may be made of any suitable absorbent plug or body, such as foamed metal or plastic material, polypropylene, terylene, nylon fiber, or ceramic. The liquid aerosol-forming substrate may be held in the porous carrier material before use of the aerosol generator, or, alternatively, the liquid aerosol-forming substrate material may be released into the porous carrier material during or immediately before use. For example, the liquid aerosol-forming substrate may be provided in a capsule. The capsule shell preferably melts upon heating, releasing the liquid aerosol-forming substrate into the porous carrier material. The capsules may optionally contain a solid combined with a liquid.

[0050] Alternatively, the carrier may be a nonwoven fiber or bundle of fibers in which tobacco components are incorporated. The nonwoven fiber or bundle of fibers may include, for example, carbon fibers, natural cellulose fibers, or cellulose derivative fibers.

[0051] Here, we will further describe the examples with reference to the following figures. [Brief explanation of the drawing]

[0052] [Figure 1] Figure 1 is a schematic cross-sectional view showing an aerosol generator according to an embodiment of the present disclosure and the interior of an aerosol generating article housed within the aerosol generator. [Figure 2A] Figure 2A is a schematic cross-sectional view showing an aerosol generator according to another embodiment of the present disclosure and the interior of an aerosol generating article housed within the aerosol generator. [Figure 2B] Figure 2B is a magnified view of a portion of the aerosol generator shown in Figure 2A, enclosed by the dashed box A. [Figure 3A] Figure 3A is a schematic cross-sectional view showing an aerosol generator according to another embodiment of the present disclosure and the interior of an aerosol generating article housed within the aerosol generator. [Figure 3B] Figure 3B is a magnified view of a portion of the aerosol generator shown in Figure 3A, enclosed by the dashed box B. [Figure 4A] Figure 4A is a schematic cross-sectional view of an aerosol generating article for use in conjunction with the aerosol generating device of this disclosure. [Figure 4B] Figure 4B is a schematic cross-sectional view of another aerosol generating article for use in conjunction with the aerosol generating device of this disclosure. [Modes for carrying out the invention]

[0053] Referring to Figure 1, this shows a schematic cross-sectional view of the interior of the aerosol generator 100 and the aerosol generating article 200 housed within the aerosol generator 100. Together, the aerosol generator 100 and the aerosol generating article 200 form an aerosol generating system. In Figure 6, the aerosol generator 100 and the aerosol generating article are shown in a simplified manner. Specifically, the elements of the aerosol generator 100 and the aerosol generating article 200 are not drawn to actual size. Furthermore, elements not relevant to understanding the aerosol generator 100 have been omitted.

[0054] The aerosol generator 100 comprises a housing 102, a power supply 104, a control circuit 106, a heater casing 108, a heating chamber 110, and a tubular casing 112. The heating chamber 110 defines a cavity for housing an aerosol generating article 200 and has a flexible heating element (not shown) disposed around it to heat the heating chamber 110 and subsequently the aerosol generating article 200. The heater casing 108 surrounds the heating chamber 110 and prevents aerosols generated in the heating chamber 110 from leaking into the aerosol generator 100. The heater casing 108 may also include an insulating material (not shown) to reduce heat loss from the heating chamber 110 to the housing 102. The power supply 104 comprises a battery, which in this embodiment is a rechargeable lithium-ion battery. The control circuit 106 is connected to both the power supply 104 and the heating element and controls the supply of electrical energy from the power supply 104 to the heating element to regulate the temperature of the heating element.

[0055] The aerosol generator 100 includes an opening 114 formed within the housing 102 at the proximal or oral end of the aerosol generator 100, through which the aerosol generating article 200 can be inserted into the heating chamber 110. The aerosol generating article 200 is longer than the cavity partially defined by the heating chamber 110 inside the aerosol generator, and therefore the proximal or oral end of the aerosol generating article 200 protrudes from the aerosol generator 100 when the aerosol generating article 200 is fully inserted.

[0056] The aerosol generating article 200 includes an aerosol forming substrate 202 disposed within the aerosol generating article such that the aerosol forming substrate 202 is positioned within the heating chamber 110 when the aerosol generating article is fully inserted into the aerosol generating device. The aerosol generating article 200 may also include other components disposed along the length of the aerosol generating article 200, as will be described in more detail below with reference to Figures 4A and 4B.

[0057] The aerosol generator 100 further includes an air intake port 116 formed within the housing 102 at the distal end of the aerosol generator 100. The tubular casing 112 has a hollow interior and provides an airflow channel 118 that defines an airflow path extending between the air intake port 116 and the heating chamber 110. The airflow channel 118 allows fluid communication between the external atmosphere of the air intake port 116 and the aerosol generating article 200 located inside the heating chamber 110. The tubular casing 112 has a flange 120 that connects to the heater casing 108 and hermetically seals the tubular casing 112 and the heater casing 108.

[0058] The airflow channel 118 comprises a first airflow channel section 118a and a second airflow channel section 118b. The first airflow channel section 118a has an inner diameter d of 1 millimeter, and the second airflow channel section 118b has an inner diameter D of 4.2 millimeters. Therefore, the internal cross-sectional area of ​​the first airflow channel section 118a is less than 1 / 16th of the internal cross-sectional area of ​​the second airflow channel section 118b. The smaller internal cross-sectional area of ​​the first airflow channel section 118 creates a limitation on the airflow path within the first airflow channel section 118a.

[0059] The first airflow channel 118a extends 15 millimeters downstream from the air intake 116, where it aligns with the increased diameter D of the second airflow channel 118b. This arrangement restricts the airflow at the air intake 116. The inventors confirmed that the limitations of a diameter of 1 millimeter and a length of 15 millimeters produce an RTD of 60 millimeters of water column. However, it will be understood that different RTDs can be achieved by varying these dimensions.

[0060] Therefore, the aerosol generator 100 produces an RTD similar to that of conventional cigarettes. This means that because a large RTD is produced by the aerosol generator 100, the aerosol generator 100 can deliver the required RTD without being overly dependent on the characteristics of the aerosol generating article 200. Furthermore, because a large RTD is produced by the aerosol generator 100 and its dimensions and structure are fixed, the RTD value is relatively constant and repeatable. Moreover, the aerosol generating article 200 can be configured to have a significantly lower RTD than the aerosol generator 100, so that the majority of the RTD is produced by the aerosol generator 100. This also means that the aerosol generating article 200 does not significantly increase the RTD when used with the aerosol generator 100.

[0061] During use, the user inserts the aerosol generating article 200 into the aerosol generator 100 through the opening 114, thereby placing the aerosol forming substrate 202 inside the heating chamber 110. Next, the user activates the aerosol generator 100, thereby supplying power to the control circuit 106 from the power supply 104 to the heating elements arranged around the heating chamber 110, thereby controllingly heating the aerosol forming substrate 202 located inside the heating chamber 110. This releases volatile compounds within the aerosol forming substrate 202, forming an aerosol. The user inhales the aerosol from the end of the aerosol generating article 200 protruding from the aerosol generator 200. By applying suction force to the aerosol generating article 200 with their mouth, the user generates a pressure drop within the aerosol generating article 200, which is in fluid communication with the air intake 116 of the aerosol generator 100 via the airflow channel 118. The pressure drop draws air into the aerosol generator 100 through the air intake 116 and flows it through the airflow channel 118 to the aerosol generating article 200. The air takes in the aerosol and passes through the aerosol generating article 200, which is then delivered to the user.

[0062] Figure 2A shows a schematic cross-sectional view of the interior of another aerosol generator 300, which houses the aerosol generating article 200. The structure of the aerosol generator 300 and the aerosol generating article 200 in Figure 2A is identical to that of Figure 1, except that the first airflow channel portion 318a of the airflow channel 318 is tapered. Figure 2B is an enlarged view of a portion of the aerosol generator 300 of Figure 2A, enclosed by a dashed box A, showing the first airflow channel portion 318a in more detail. The taper of the first airflow channel portion 318a is exaggerated in Figures 2A and 2B to more clearly illustrate the feature.

[0063] Similar to the aerosol generator 100 in Figure 1, the first airflow channel section 318a and the second airflow channel section 318b of the aerosol generator 300 in Figures 2A and 2B are formed within a tubular casing 312. The first airflow channel section 318a has an outlet diameter d1 at its downstream end that is smaller than the inlet diameter d2 at its upstream end. The first airflow channel section 318a has an outlet diameter d1 of 1.20 mm and an inlet diameter d2 of 1.32 mm. Thus, the outlet diameter d1 is approximately 9-10 percent smaller than the inlet diameter d2. Both the outlet diameter d1 and the inlet diameter d2 are smaller than the diameter D of the second airflow channel section 318b, which is 4.2 mm. Thus, the smaller internal cross-sectional area of ​​the first airflow channel section 318a results in limitations on the airflow path within the first airflow channel section 318a. The diameter of the first airflow channel 318a decreases linearly between the upstream and downstream ends of the first airflow channel 318a.

[0064] The first airflow channel 318a extends 15 millimeters downstream from the air intake 316, where it aligns with the increased diameter D of the second airflow channel 318b. This configuration restricts the airflow at the air intake 316. The configuration in Figure 2B has been found to result in an effective RTD for the aerosol generator 300. However, it will be understood that different RTDs can be achieved by changing the dimensions.

[0065] Figure 3 shows a schematic cross-sectional view of the interior of another aerosol generator 400, which houses the aerosol generating article 200. The structure of the aerosol generator 400 and the aerosol generating article 200 in Figure 3A is identical to that of Figure 1, except that the first airflow channel portion 418a of the airflow channel 418 is equipped with a removable plug 420. Figure 3B is a magnified view of a portion of the aerosol generator 400 of Figure 3A, enclosed by a dashed box B, showing the removable plug 420 in more detail.

[0066] Similar to the aerosol generator 100 in Figure 1, the second airflow channel section 418b of the aerosol generator 400 in Figures 3A and 3B is formed within a tubular casing 412. As described above, the first airflow channel section 418a includes a removable plug 420. The removable plug 420 has a through hole 422 extending between its opposing ends, defining an airflow path through the removable plug 420. The through hole 422 formed within the removable plug 420 has an inner diameter d of 1 millimeter. The second airflow channel section 418b formed within the tubular casing 412 has an inner diameter D of 4.2 millimeters. Therefore, the smaller internal cross-sectional area of ​​the through hole 422 causes a limitation of the airflow path within the first airflow channel section 318a formed by the removable plug 420.

[0067] The removable plug 420 has a narrower insertion portion 424, which is inserted into the distal end of the tubular casing 412 and configured to connect the through-hole 422 to the second airflow channel portion 418b. The removable plug 420 is held in place within the tubular casing by a tight fit between the tubular casing 412 and the insertion portion 424. The removable plug 420 has a length of 15 millimeters. The distal end of the through-hole 422 forms an air intake 416, and thus the narrow through-hole 422 restricts the airflow at the air intake 416. The arrangement in Figure 3B has been found to result in an effective RTD for the aerosol generator 400. However, it will be understood that different RTDs can be achieved by changing the dimensions. In fact, it may be possible to use different removable plugs having through-holes of different cross-sectional areas to allow the user to configure the aerosol generator to have a preferred RTD.

[0068] Figure 4A shows a schematic cross-sectional view of an aerosol generating article 500 for use with any of the aerosol generating devices described above. The aerosol generating article 500 comprises an end plug 504, an aerosol forming substrate 502, a hollow tube 506, and a mouthpiece filter 508. Each of the above-described components of the aerosol generating article 500 is substantially cylindrical, and each has substantially the same diameter. The components are arranged coaxially, in contact with each other, and continuously, and are surrounded by an outer paper wrapper 510 to form a cylindrical rod. The aerosol forming substrate 502 is a tobacco rod or plug comprising an assembly of crumpled sheets of homogenized tobacco material surrounded by a wrapper (not shown). The crumpled sheets of homogenized tobacco material contain glycerin as an aerosol former. The end plug 504 and the mouthpiece filter 508 are formed from cellulose acetate fibers.

[0069] Figure 4B shows a schematic cross-sectional view of another aerosol generating article 600 for use in conjunction with any of the aerosol generating devices described above. The aerosol generating article 600 comprises a tobacco rod 601 and a downstream section 605 disposed downstream of the tobacco rod. The tobacco rod 601 comprises an aerosol-forming substrate 602 encased in a plug wrap 603. The aerosol-forming substrate 602 contains about 12 weight percent of an aerosol-forming material, for example, a tobacco cut filler impregnated with glycerin. The tobacco cut filler contains 90 weight percent of tobacco leaf laminas. The cut width of the tobacco cut filler is about 0.7 millimeters. The aerosol-forming substrate 12 comprises about 130 milligrams of tobacco cut filler.

[0070] The downstream section 605 comprises a hollow tubular element 606 positioned immediately downstream of the tobacco rod 601 of the aerosol generating substrate. The hollow tubular element 606 is aligned with the tobacco rod 601 in the longitudinal direction and is combined with the tobacco rod 601 by an outer wrapper 607. In the embodiment shown in Figure 4B, the upstream end of the hollow tubular element 606 abuts against the downstream end of the tobacco rod 601.

[0071] The hollow tubular element 606 comprises a hollow cylindrical tube made of cellulose acetate or rigid paper, for example, paper having a basis weight (basic weight) of at least about 90 grams per square meter. The hollow tubular element 606 defines an internal cavity 608 that extends all the way from the upstream end of the hollow tubular element 606 to the downstream end of the hollow tubular element 606. The internal cavity 608 is substantially empty, and therefore substantially unrestricted airflow is possible through the internal cavity 608.

[0072] The tobacco rod 1 has an RTD of approximately 18 millimeters of water column. The hollow tubular element 606 has a very small RTD. As a result, the hollow tubular element 606 does not contribute substantially to the overall RTD of the aerosol generating article 10, and the overall RTD is substantially the same as that of the tobacco rod 601. Therefore, the aerosol generating article 600 has a significantly lower RTD than the aerosol generating device, as the majority of the RTD is generated by the aerosol generating device. This also means that the aerosol generating article 600 does not significantly increase the RTD when used in an aerosol generating device.

[0073] For the purposes of this specification and the appended claims, unless otherwise indicated, all figures representing amounts, quantities, percentages, etc., should be understood in all cases as being modified by the term “approximately.” Furthermore, all ranges include the disclosed maximum and minimum points and any intermediate ranges therewith, which may or may not be specifically listed herein. Thus, in this context, number A is understood as 5 percent of A ± A. In this context, number A may be considered to include a numerical value that falls within the general standard error of the measurement of the characteristic modified by number A. In some cases, such as those used in the appended claims, number A may deviate by the percentages listed above, provided that the amount by which A deviates does not substantially affect the fundamental and novel characteristics of the claimed invention.

Claims

1. Aerosol generator, Air intake and A cavity for containing at least a portion of the aerosol-generating article, An airflow channel that defines an airflow path extending between the air intake and the cavity, The airflow channel comprises a first airflow channel section and a second airflow channel section, wherein the cross-sectional area of ​​the airflow path in the first airflow channel section is smaller than the cross-sectional area of ​​the airflow path in the second airflow channel section, and the aerosol generator is configured to restrict the airflow within the first airflow channel section. An aerosol generator comprising an airflow channel having an extraction resistance of 25 millimeters of water column to 70 millimeters of water column when passing through the airflow channel.

2. The aerosol generator according to claim 1, wherein the end of the first airflow channel is disposed at the air intake to restrict the airflow path at the air intake.

3. The aerosol generator according to claim 1 or 2, wherein the ratio of the cross-sectional area of ​​the airflow path in the second airflow channel to the cross-sectional area of ​​the airflow path in the first airflow channel is 10:1 to 100:

1.

4. The aerosol generator according to claim 3, wherein the ratio of the cross-sectional area of ​​the airflow path in the second airflow channel to the cross-sectional area of ​​the airflow path in the first airflow channel is 10:1 to 20:

1.

5. The aerosol generator according to any one of claims 1 to 4, wherein the ratio of the length of the second airflow channel to the length of the first airflow channel is 5:1 to 1:

1.

6. The aerosol generating apparatus according to any one of claims 1 to 5, wherein the first airflow channel portion is tapered.

7. The aerosol generator according to claim 6, wherein the first airflow channel has an outlet width or diameter at the downstream end of the first airflow channel that is smaller than the inlet width or diameter at the upstream end of the first airflow channel.

8. The aerosol generator according to claim 6, wherein the first airflow channel has an outlet width or diameter at the downstream end of the first airflow channel that is larger than the inlet width or diameter at the upstream end of the first airflow channel.

9. The aerosol generator according to claim 8, wherein the outlet width or diameter of the first airflow channel is 5 to 15 percent larger than the inlet width of the first airflow channel.

10. The aerosol generator according to any one of claims 1 to 9, wherein the airflow channel comprises a tubular casing, the inner surface of the tubular casing defines the airflow path, and the first airflow channel portion of the tubular casing has an internal width or diameter of 0.5 mm to 2 mm.

11. The aerosol generating apparatus according to claim 10, wherein the first and second airflow channel sections are integrally formed within the tubular casing.

12. The aerosol generator according to any one of claims 1 to 10, wherein the first airflow channel portion comprises a removable plug configured to connect to the second airflow channel portion, the plug having a through hole extending between its opposing ends, and defining an airflow path through the plug.

13. The aerosol generating apparatus according to any one of claims 1 to 12, further comprising a heater for heating the aerosol generating article within the cavity.

14. An aerosol generating system comprising an aerosol generating device according to any one of claims 1 to 13 and an aerosol generating article, wherein the aerosol generating article includes an aerosol forming substrate.

15. The aerosol generating system according to claim 14, wherein the aerosol generating article has a draw resistance of less than 50 percent of the draw resistance of the airflow channel of the aerosol generating device.

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