Cartridge for use in an aerosol generating system

Abstract

A cartridge (200) for use in an aerosol generation system (100) is provided. The cartridge (200) comprises a reservoir (303) for a liquid aerosol-forming substrate, a heating element (304) for heating the liquid aerosol-forming substrate from the reservoir (303), and a wall (307). A first space adjacent to the heating element (304) and between the wall (307) and the heating element (304) forms a hot zone (306). A second space adjacent to the heating element (304) forms a feed zone (308). The reservoir (303) is in fluid communication with the feed zone (308) and the hot zone (306). An aerosol generation system is also provided.

Description

[Technical field]

[0001] The present disclosure relates to a cartridge for use in an aerosol generation system. The present disclosure also relates to an aerosol generation system comprising the aforementioned cartridge. [Background technology]

[0002] In many known aerosol generating systems, a liquid aerosol-forming substrate is heated and vaporized to form a vapor. The vapor is cooled to form an aerosol. In some aerosol generating systems, such as electrically heated smoking systems, this aerosol is then inhaled by the user.

[0003] Typically, the liquid aerosol-forming substrate contains several compounds that are vaporized when heated. These compounds may have different boiling points. For example, the liquid aerosol-forming substrate may contain nicotine (which has a boiling point of about 247 degrees Celsius at atmospheric pressure) and glycerol (which has a boiling point of about 290 degrees Celsius at atmospheric pressure).

[0004] When a liquid aerosol-forming substrate containing compounds with different boiling points is heated, the compound with the lower boiling point may be vaporized before the compound with the higher boiling point. Alternatively, or in addition, the compound with the lower boiling point may be vaporized at a higher rate than the compound with the higher boiling point.

[0005] This may be undesirable because the interaction and combination between different compounds may be limited.For example, the liquid aerosol-forming substrate may include a nicotine compound and an organic acid compound, and these compounds have different boiling points. Both of these compounds may be vaporized. The nicotine in the liquid aerosol-forming substrate may form a free base nicotine when vaporized. However, it may be desirable to generate an aerosol with a nicotine salt, rather than a free base nicotine. To form this nicotine salt, the free base nicotine may be protonated by the vaporized organic acid. However, if the organic acid is not vaporized until the nicotine is vaporized, or is vaporized slower than required to protonate the appropriate proportion of the free base nicotine, this protonation may be limited.

[0006] Furthermore, vaporizing some compounds of the aerosol-forming substrate more quickly than others can undesirably change the properties of the generated aerosol over time, for example, during the course of a puff in the aerosol-generating system. This is because when the heating element is activated and the temperature rises towards the beginning of a puff, the liquid aerosol-forming substrate close to the heating element can reach a first temperature at which a first compound with a low boiling point is vaporized, but not a second compound with a high boiling point. Then, in a subsequent puff, the liquid aerosol-forming substrate close to the heating element can reach a second temperature at which a second compound with a high boiling point is vaporized. However, at this time, most of the first compound in the liquid aerosol-forming substrate close to the heating element may already be vaporized. Thus, the aerosol generated towards the beginning of a puff may contain a greater proportion of the first compound, and the aerosol generated in a subsequent puff may contain a greater proportion of the second compound.

[0007] Alternatively, or in addition, the properties of the generated aerosol may change over the course of several puffs. This may occur if the compounds of the liquid aerosol-forming substrate are not vaporized at an appropriate rate. For example, the liquid aerosol-forming substrate may contain X% by weight of a first compound and Y% by weight of a second compound. If the liquid aerosol-forming substrate is not vaporized to produce a vapor containing a mass ratio of the first compound to the second compound of X:Y, the composition of the liquid aerosol-forming substrate may change as the vapor is generated. This may then lead to a change in the properties of the aerosol generated by the liquid aerosol-forming substrate. Summary of the Invention

[0008] An object of the present invention is to control the vaporization of various compounds of a liquid aerosol-forming substrate, these compounds having different boiling points.

[0009] According to one aspect of the disclosure, there is provided a cartridge for use in an aerosol generation system. The cartridge may comprise a reservoir for a liquid aerosol-forming substrate. The cartridge may comprise a heating element for heating the liquid aerosol-forming substrate from the reservoir. The cartridge may comprise a wall. A first space may be adjacent to the heating element and between the wall and the heating element. The first space may form a high temperature zone. The second space may be adjacent to the heating element. The second space may form a feed zone. The reservoir may be in fluid communication with the feed zone and the high temperature zone.

[0010] In use, the hot zone may be heated to a higher temperature than the feed zone. Alternatively, or in addition, in use, the hot zone may increase in temperature at a faster rate than the feed zone. Both the hot zone and the feed zone may be heated to a temperature sufficient to vaporize at least one compound in the liquid aerosol-forming substrate. Thus, in use, the cartridge may provide hot and cold regions in which the liquid aerosol-forming substrate is vaporized.

[0011] Advantageously, the cartridge may improve control of vaporization of different compounds of the liquid aerosol-forming substrate. The cartridge may simultaneously vaporize liquid aerosol-forming substrate compounds having high and low boiling points at a desired rate. The cartridge may vaporize liquid aerosol-forming substrate compounds having high and low boiling points in a more favorable ratio. The cartridge may provide for the generation of aerosols having a more desirable composition. The cartridge may provide for a more consistent generation of aerosols having desirable properties.

[0012] In use, the hot zone may be heated to a first temperature. In use, the feed zone may be heated to a second temperature. The first temperature may be greater than the second temperature. The first temperature may be at least 5, 10, 20, or 30 degrees Celsius greater than the second temperature.

[0013] Advantageously, the large temperature differential between the hot zone and the feed zone allows liquid aerosol-forming substrate compounds having high and low boiling points to be vaporized at a more favorable rate or at a more favorable proportion, or both at a more favorable rate and at a more favorable proportion.

[0014] The reservoir may be configured to or may store at least 0.2, 0.5, or 1 milliliter of the liquid aerosol-forming substrate. The reservoir may be configured to or may store less than 2, 1.8, or 1.5 milliliters of the liquid aerosol-forming substrate.

[0015] The wall may be located within the reservoir. The wall may form a periphery of the reservoir. The wall may be in contact with the reservoir. The wall may be in contact with the feed zone. The wall may be in contact with the high temperature zone. At least a portion of the wall may be located between the feed zone and the reservoir. At least a portion of the wall may be located between the high temperature zone and the reservoir. In use, the liquid aerosol-forming substrate may be disposed on two opposing sides of the wall. In use, the liquid aerosol-forming substrate may be in contact with two opposing sides of the wall.

[0016] The feed zone may be adjacent to an opening in the wall. The feed zone may be adjacent to an edge of the wall. The wall may be parallel to the heating element. The wall may have substantially the same shape as the heating element.

[0017] The wall may insulate the heating element, or at least a portion of the heating element, from the reservoir. The wall may insulate the hot zone from the reservoir. The wall may insulate the feed zone from the reservoir. The wall, or the material forming the wall, may have a thermal conductivity that is at least 10, 20, 30, 40, 50, 60, or 70% less than the thermal conductivity of the liquid aerosol-forming substrate. Thus, the provision of the wall at least partially results in a hot zone and a relatively cool feed zone.

[0018] Advantageously, this may improve the energy efficiency of the cartridge as less heat may be dissipated into the reservoir from the heating element, or from the hot zone, or from the supply zone.

[0019] The high temperature zone may be insulated from the feed zone, so if the feed zone and high temperature zone are raised to the same temperature and then cooled, the initial cooling rate of the feed zone may be greater than the initial cooling rate of the high temperature zone.

[0020] Advantageously, this can help to increase or maintain the temperature differential between the supply zone and the hot zone during use.

[0021] A portion of the wall in contact with the feed zone may be thinner than a portion of the wall in contact with the hot zone. The wall may insulate the feed zone from the reservoir to a lesser extent than the wall insulates the hot zone from the reservoir.

[0022] Advantageously, this can help to increase or maintain the temperature differential between the supply zone and the hot zone during use.

[0023] In use, the liquid aerosol-forming substrate may be transported from the reservoir to the feed zone. In use, the liquid aerosol-forming substrate may be transported from the reservoir via the feed zone towards the heating element. In use, the liquid aerosol-forming substrate may be transported from the feed zone to the high temperature zone. In use, the liquid aerosol-forming substrate may be transported from the reservoir to the high temperature zone via the feed zone.

[0024] In use, the liquid aerosol-forming substrate may be transported from the reservoir to the high temperature zone only via the feed zone, i.e. the cartridge may be configured such that the liquid aerosol-forming substrate in the reservoir must be transported through the feed zone to reach the high temperature zone.

[0025] Advantageously, conveying the liquid aerosol-forming substrate through the feed zone to the high temperature zone may mean that the liquid aerosol-forming substrate reaching the high temperature zone is already heated to some extent, since the feed zone may be adjacent to a heating element, in this sense the liquid aerosol-forming substrate reaching the high temperature zone may be preheated.

[0026] The cartridge may include a passage, for example a constricted passage. The passage may connect the reservoir to the feed zone. In use, the liquid aerosol-forming substrate may be transported from the reservoir to the feed zone via the passage. In use, the liquid aerosol-forming substrate may be transported from the reservoir to the hot zone and then to the feed zone via the passage.

[0027] In use, the liquid aerosol-forming substrate may be transported from the reservoir to the hot zone and then to the feed zone only via the passageway. That is, the cartridge may be configured such that the liquid aerosol-forming substrate in the reservoir must be transported through the passageway and then to the feed zone to reach the hot zone. The wall may form a periphery of the passageway.

[0028] Advantageously, the passageway, or narrowed passageway, may reduce heat dissipation from the heating element or hot or supply zone into the reservoir.

[0029] The cartridge may include an air inlet. The cartridge may include an air outlet. An airflow path may be defined between the air inlet and the air outlet. Air drawn from the air inlet to the air outlet may flow across, over, through or through the heating element.

[0030] Advantageously, in use, this can increase the temperature of the airflow, which some users may prefer, and which can more accurately mimic the experience of smoking a traditional cigarette or cigar.

[0031] The heating element may at least partially surround or encircle the airflow path. For example, the heating element may surround at least 180 degrees, 225 degrees, 270 degrees, or 315 degrees of the airflow path. As an example, the cross section of the heating element may form seven sides of a regular octagon. Air may flow through an air inlet, then through the center of the octagon, and then through an air outlet. As another example, the heating element may be prismatic with a base that forms a 300-degree circle, and a length that extends perpendicularly from the base. Air may flow through an air inlet, then through the center of the base, then along the length of the heating element, and then through an air outlet.

[0032] The heating element may surround or encircle the airflow path. For example, the cross section of the heating element may form a closed two-dimensional shape, such as a circle or a polygon. Air may flow through an air inlet, then through this closed two-dimensional shape formed by the cross section of the heating element, and then through an air outlet. As another example, the heating element may be in the shape of a hollow cylinder, and air may flow through an air inlet, then through the hollow cylinder, and then through an air outlet.

[0033] Advantageously, the heating element may at least partially surround or encircle the airflow path, thereby increasing the amount of airflow in contact with the heating element, which may increase the average temperature of the airflow, and which may increase the amount of vapor formed by the heating element that is entrained in the airflow.

[0034] Two or more airflow paths may be defined within the cartridge. For example, the cartridge may include multiple air inlets, or multiple air outlets, or both multiple air inlets and multiple air outlets. Alternatively, or in addition, the airflow path from the air inlets may split into two or more airflow paths. Alternatively, or in addition, two or more airflow paths of the cartridge may merge and exit through a single air outlet.

[0035] Advantageously, this may allow for adjustment of the average temperature of the aerosol delivered to the user, since one or more airflow paths may be heated and one or more other airflow paths may not be heated. Furthermore, this may allow for adjustment of the draw resistance of the cartridge. For example, adding additional air intakes may allow the user to draw a larger air flow through the cartridge for a given inhalation strength at the air outlet.

[0036] The heating element, or a portion thereof, may comprise an electrically resistive material. The cartridge may be configured such that, in use, an electric current is passed through the heating element, or a portion thereof. This may resistively heat said heating element, or a portion thereof. Thus, the heating element, or a portion thereof, may be configured to be resistively heated.

[0037] The heating element, or a portion thereof, may include or be formed from any material having suitable electrical and mechanical properties, for example, a suitable electrically resistive material. Suitable materials include, but are not limited to, semiconductors such as doped ceramics, "conductive" ceramics (e.g., molybdenum disilicide, etc.), carbon, graphite, metals, alloys, and composites made of ceramic and metallic materials. Such composites may include doped or undoped ceramics. Examples of suitable doped ceramics include doped silicon carbide. Examples of suitable metals include titanium, zirconium, tantalum, and platinum group metals. Examples of suitable alloys include stainless steel, constantan, nickel-containing, cobalt-containing, chromium-containing, aluminum-containing, titanium-containing, zirconium-containing, hafnium-containing, niobium-containing, molybdenum-containing, tantalum-containing, tungsten-containing, tin-containing, gallium-containing, manganese-containing, and iron-containing alloys, and nickel, iron, cobalt, stainless steel-based superalloys, Timetal®, iron-aluminum-based alloys, and iron-manganese-aluminum-based alloys. Timetal® is a registered trademark of Titanium Metals Corporation, 1999 Broadway Suite 4300, Denver Colorado. In composite materials, the electrically resistive material may be embedded in, encapsulated in, or coated with an insulating material, or vice versa, depending on the required energy transfer kinetics and external physicochemical properties. The heating element, or a portion thereof, may include a metallic etched foil insulated between two layers of inert material. In that case, the inactive material may include Kapton®, an all-layer polyimide, or a mica foil. Kapton® is a registered trademark of EI du Pont de Nemours and Company, 1007 Market Street, Wilmington, Delaware 19898, United States of America.

[0038] The heating element may include a first portion and a second portion. The first portion may be configured to be heated to a higher temperature than the second portion.

[0039] Advantageously, this may allow for the creation of more hot and more cold regions. This may allow for a more favorable rate of vaporization of compounds of the liquid aerosol-forming substrate having high and low boiling points. Alternatively, or in addition, this may allow for a larger temperature difference between the hot zone and the feed zone. This may be the case when the first portion is located closer to the hot zone than the feed zone, or when the second portion is located closer to the feed zone than the hot zone, or when both the first portion is located closer to the hot zone than the feed zone and the second portion is located closer to the feed zone than the hot zone.

[0040] The heating element, or the first portion, or the second portion, or both the first and second portions of the heating element, may be configured to be heated to at least 50, 100, 150, 200, 250, 300, 350, or 400 degrees Celsius. In use, the heating element, or the first portion, or the second portion, or both the first and second portions of the heating element may be heated to at least 50, 100, 150, 200, 250, 300, 350, or 400 degrees Celsius.

[0041] The first portion may have one or more of a first electrical resistance, a first electrical resistivity, and a first average cross-sectional area. The second portion may have one or more of a second electrical resistance, a second electrical resistivity, and a second average cross-sectional area. The first electrical resistance may be greater than the second electrical resistance. The first electrical resistivity may be greater than the second electrical resistivity. The first average cross-sectional area may be less than the second average cross-sectional area.

[0042] Advantageously, this may allow the first portion to be heated to a higher temperature than the second portion.

[0043] The second portion may include a section that is disposed so that it contacts itself, for example, the section may be folded or curved so that the section contacts itself.

[0044] Advantageously, when the second portion is resistively heated, this may reduce the electrical resistance of the second portion, thereby reducing the temperature to which the second portion is heated.

[0045] The heating element, or a portion thereof, may include a susceptor material. The cartridge may be configured for use in an aerosol generation system that includes an inductor, such as an induction coil. The inductor may be disposed within an aerosol generation device having a power source. The device may be configured to engage with the cartridge. Alternatively, the inductor may be disposed within the cartridge. The cartridge may be configured to engage with an aerosol generation device having a power source.

[0046] The power source may be configured to pass a current through an inductor in the cartridge, or through an inductor in the device, such that the inductor generates a changing or oscillating electromagnetic field.

[0047] The alternating current may have any suitable frequency. The alternating current may be a high frequency alternating current. The alternating current may have a frequency between 100 kilohertz (kHz) and 30 megahertz (MHz). If the inductor is a tubular inductor coil, the alternating current may have a frequency between 500 kilohertz (kHz) and 30 megahertz (MHz). If the inductor is a planar inductor coil, the alternating current may have a frequency between 100 kilohertz (kHz) and 1 megahertz (MHz).

[0048] The heating element may be disposed within or otherwise subjected to an electromagnetic field generated by the inductor. This may generate eddy currents and hysteresis losses in the susceptor material. This may heat the susceptor material. Thus, the power supply and inductor may be configured to inductively heat the heating element, or a portion thereof.

[0049] The susceptor material may be or include any material that can be inductively heated to a temperature sufficient to generate an aerosol from the aerosol-forming substrate. Preferred susceptor materials may be heated to temperatures in excess of 50, 100, 150, 200, 250, 300, 350, or 400 degrees Celsius. Preferred susceptor materials may include metal, or carbon, or both metal and carbon. Preferred susceptor materials may include ferromagnetic materials, such as ferritic iron, or ferromagnetic steel or stainless steel. Suitable susceptor elements may be or include one or more of graphite, molybdenum, silicon carbide, stainless steel, niobium, and aluminum. Preferred susceptor materials may include or be formed from 400 series stainless steel, such as grade 410, or grade 420, or grade 430 stainless steel. Different materials dissipate different amounts of energy when placed in electromagnetic fields having similar values ​​of frequency and field strength. Thus, the parameters of the susceptor material, such as material type, size, etc., may be modified to provide a desired power dissipation within a known electromagnetic field.

[0050] Advantageously, in an aerosol generating system using induction heating, it is not necessary to form electrical contacts between the heating element and the aerosol generating device. Furthermore, the heating element may not need to be electrically coupled to other components. This may eliminate the need for solder or other coupling elements. Cartridges incorporating heating elements configured to be inductively heated may allow for the manufacture of simple, inexpensive, and robust cartridges. Cartridges are typically manufactured in much larger quantities than the aerosol generating devices with which they operate. Thus, reducing the cost of the cartridges may translate into significant cost savings for manufacturers. Furthermore, induction heating may provide improved energy conversion compared to resistive heating, since induction heating may not have the power losses associated with electrical resistance in the connection between a resistive heating element and a power source.

[0051] The first portion may include one or more of curves, folds, corrugations, and undulations, which may increase the volume or surface area of ​​the first portion present in a given volume, which may advantageously allow the first portion to transfer more heat to a given volume.

[0052] A curve may refer to a gradual change in direction. Thus, a curve may form an arc, or a "C" shape.

[0053] A fold may refer to a step in direction. Thus, a fold may form two sides of a polygon, or a "V" shape.

[0054] The undulations may include multiple curves. For example, the undulations may refer to a gradual change in direction in a first direction followed by a gradual change in another direction, e.g., the opposite direction. Thus, the undulations may form a sine wave, or "S" shape.

[0055] A corrugation may include multiple folds. For example, a corrugation may refer to a step in one direction followed by another step in the next direction. Thus, a corrugation may form three sides of a rectangle, or an "M" shape, or an "N" shape.

[0056] Advantageously, one or more of the curves, undulations, folds, and corrugations may enable the first portion to heat a given volume to a higher temperature. For example, the first portion may include a tightly curved "S" shape. The area around the tightly curved "S" shape of the first portion may be heated to a higher temperature than if the tightly curved "S" shape were not present.

[0057] The cross-section, or cross-sectional area, of the heating element may vary. For example, the average cross-sectional area of ​​the first portion may be at least 5, 10, 20, 30, or 50% less than the average cross-sectional area of ​​the second portion.

[0058] Advantageously, if the heating element is arranged to be resistively heated, this allows a first portion to have a higher electrical resistance and be heated to a higher temperature than a second portion.

[0059] The first portion may be located closer to the high temperature zone than the second portion. The second portion may be located closer to the feed zone than the first portion. The first portion may be adjacent to the high temperature zone, in contact with the high temperature zone, or both adjacent to and in contact with the high temperature zone. The first portion may not be in contact with the feed zone. The second portion may be adjacent to the feed zone, in contact with the feed zone, or both adjacent to and in contact with the feed zone. The first portion may not be in contact with the high temperature zone.

[0060] Advantageously, this may allow the first portion to heat the high temperature zone more than the second portion heats the high temperature zone. Alternatively, or in addition, this may mean that heat from the first portion is transferred to the high temperature zone more than to the supply zone. This may help to increase or maintain the temperature difference between the high temperature zone and the supply zone in use.

[0061] The cartridge may comprise a support for the heating element. The heating element may be in contact with the support. A second portion of the heating element may be in contact with the support. A first portion of the heating element may not be in contact with the support. The heating element may be fixed to the support or at least partially fixed in place by the support.

[0062] Advantageously, the support may fix the heating element in place.

[0063] The wall may form a support.

[0064] Advantageously, the walls forming the support may eliminate the need for a separate structure separate from the walls to form the support, which may allow for cheaper production of the cartridge.

[0065] In use, the liquid aerosol-forming substrate in the feed zone may be vaporized. In use, the liquid aerosol-forming substrate in the high temperature zone may be vaporized. In use, the liquid aerosol-forming substrate in the feed zone and the liquid aerosol-forming substrate in the high temperature zone may be vaporized simultaneously.

[0066] Advantageously, this may increase the rate at which the liquid aerosol-forming substrate evaporates during use of the cartridge. Furthermore, the average composition of the liquid aerosol-forming substrate vaporized from the feed zone may be different from the average composition of the liquid aerosol-forming substrate vaporized from the high temperature zone. The liquid aerosol-forming substrate vaporized from the feed zone may contain a larger proportion of compounds having a relatively low boiling point than the liquid aerosol-forming substrate vaporized from the high temperature zone. The liquid aerosol-forming substrate vaporized from the high temperature zone may contain a larger proportion of compounds having a relatively high boiling point than the liquid aerosol-forming substrate vaporized from the feed zone. Thus, liquid aerosol-forming substrate compounds having high and low boiling points may be vaporized simultaneously at a desired rate and in a more favorable proportion. Aerosols with more desirable compositions may be generated. Aerosols with desirable properties may be generated more consistently.

[0067] The feed zone may be located between the wall and the heating element.

[0068] The minimum distance between the wall and the heating element through the high temperature zone may be less than the minimum distance between the wall and the heating element through the feed zone. Alternatively, or in addition, the maximum distance between the wall and the heating element through the high temperature zone may be less than the maximum distance between the wall and the heating element through the feed zone. Alternatively, or in addition, the average distance between the wall and the heating element through the high temperature zone may be less than the average distance between the wall and the heating element through the feed zone.

[0069] Advantageously, this may increase the temperature difference between the hot zone and the feed zone during use, specifically, this may result in greater heating of the hot zone.

[0070] The hot zone may be smaller than the feed zone. The hot zone may contain a smaller volume of liquid aerosol-forming substrate than the feed zone during use of the cartridge.

[0071] Advantageously, this may increase the temperature difference between the hot zone and the feed zone during use, specifically, this may result in greater heating of the hot zone.

[0072] The heating element may be perforated. The heating element may be a mesh heating element. The heating element may include a mesh. The first portion, or the second portion, or both the first and second portions may include perforations or a mesh.

[0073] Advantageously, a mesh heating element, or a heating element including a mesh, can provide a large surface area in contact with the liquid aerosol-forming substrate, which can provide efficient vaporization of the liquid aerosol-forming substrate.

[0074] The wall may be configured to hold the liquid aerosol-forming substrate. The wall may comprise or be a material that is immersed in or configured to be immersed in the liquid aerosol-forming substrate. The wall may have a fibrous or spongy structure. The wall may comprise a porous material. The wall may comprise a capillary material. The wall may comprise a bundle of capillaries. For example, the wall may comprise one or more of fibers, threads, and pore tubes.

[0075] The wall may comprise a sponge-like or foam-like material. The structure of the wall may form a plurality of small holes or channels through which liquid can be transported by capillary action.

[0076] The wall may comprise any suitable material or combination of materials. Suitable materials include, but are not limited to, sponge or foam materials, ceramic or graphite-based materials in the form of fibers or sintered powders, foamed metal or plastic materials, fibrous materials, such as spun or extruded fibers (such as cellulose acetate, polyester, or bonded polyolefin, polyethylene, terylene, or polypropylene fibers, nylon fibers, or ceramics). The wall may comprise a ceramic material. The wall may have any suitable capillary and porosity to be used with different liquid aerosol-forming substrates having different physical properties.

[0077] Advantageously, these materials may allow the liquid aerosol-forming substrate to pass through the walls, which may prevent the heating element, or hot zone, or feed zone area from drying out.

[0078] In use, the liquid aerosol-forming substrate may be able to pass through the wall. In use, the liquid aerosol-forming substrate may be able to pass from the reservoir through the wall towards the heating element. In use, the liquid aerosol-forming substrate may be able to pass from the reservoir through the wall towards or into the high temperature zone. In use, the liquid aerosol-forming substrate may be able to pass from the reservoir through the wall towards or into the feed zone.

[0079] Advantageously, the ability of the liquid aerosol-forming substrate to pass through the wall may prevent portions of the hot zone, feed zone, or heating element from drying out as the liquid aerosol-forming substrate is vaporized, which may allow for more consistent vaporization of the liquid aerosol-forming substrate.

[0080] The wall may be in fluid communication with the reservoir.

[0081] Advantageously, a wall in fluid communication with the reservoir may allow liquid aerosol-forming substrate removed from the wall to be quickly and automatically replenished with liquid aerosol-forming substrate from the reservoir.

[0082] The thermal conductivity of the wall may be less than the thermal conductivity of the liquid aerosol-forming substrate.

[0083] Advantageously, this may allow the wall to effectively insulate the heating element, or supply zone, or hot zone, from the reservoir.

[0084] The wall may not be porous. The liquid aerosol-forming substrate may not be able to pass through the wall. The wall may include or be formed from a polymeric material. Advantageously, a non-porous material may prevent the liquid aerosol-forming substrate from passing through the wall. Depending on the arrangement of the wall, this may mean that the liquid aerosol-forming substrate must pass through a feed zone to reach the high temperature zone. Thus, the liquid aerosol-forming substrate that reaches the high temperature zone may be preheated.

[0085] The shortest distance between the hot zone and the heating element may be equal to the shortest distance between the feed zone and the heating element. The hot zone may be in contact with the heating element. The feed zone may be in contact with the heating element.

[0086] The cartridge may include a second high temperature zone. The second high temperature zone may be formed by a third space adjacent to the heating element. The third space may be between the wall and the heating element. The second high temperature zone may be in contact with the heating element. The second high temperature zone may be in contact with the wall.

[0087] The features described above in relation to the first space or the high temperature zone may be applied to the third space or the second high temperature zone, respectively.

[0088] In use, the liquid aerosol-forming substrate may be transported from the supply zone to the second high temperature zone. Thus, the liquid aerosol-forming substrate may be transported from the supply zone to both the high temperature zone and the second high temperature zone. In use, the liquid aerosol-forming substrate may be transported from the reservoir to the second high temperature zone via the supply zone. In use, the liquid aerosol-forming substrate may be transported from the reservoir to the second high temperature zone only via the supply zone. That is, the cartridge may be configured such that the liquid aerosol-forming substrate in the reservoir must be transported through the supply zone to reach the second high temperature zone.

[0089] Advantageously, conveying the liquid aerosol-forming substrate through the feed zone to the second high temperature zone may mean that the liquid aerosol-forming substrate reaching the second high temperature zone is already heated, since the feed zone may be adjacent to a heating element, in this sense the liquid aerosol-forming substrate reaching the second high temperature zone may be preheated.

[0090] The cartridge may include a second feed zone, which may be formed by a fourth space adjacent the heating element.

[0091] The features described above in relation to the second space or the feed zone may be applied to the fourth space or the second feed zone, respectively.

[0092] Advantageously, the second hot zone and the second feed zone can increase the number of hot and cold regions in use. This allows liquid aerosol-forming substrate compounds having high and low boiling points to be vaporized simultaneously at a desired rate. This allows liquid aerosol-forming substrate compounds having high and low boiling points to be vaporized at a more favorable rate. This can provide for the generation of aerosols having a more desirable composition. This can provide for a more consistent generation of aerosols having desirable properties.

[0093] In use, the liquid aerosol-forming substrate may be transported from the second supply zone to the second higher temperature zone. In use, the liquid aerosol-forming substrate may be transported from the reservoir to the second higher temperature zone via the second supply zone. In use, the liquid aerosol-forming substrate may be transported from the reservoir to the second higher temperature zone only via the second supply zone. That is, the cartridge may be configured such that the liquid aerosol-forming substrate in the reservoir must be transported through the second supply zone to reach the second higher temperature zone.

[0094] Advantageously, conveying the liquid aerosol-forming substrate through the second supply zone to the second high temperature zone may mean that the liquid aerosol-forming substrate reaching the second high temperature zone is already heated, since the second supply zone may be adjacent to a heating element, in this sense the liquid aerosol-forming substrate reaching the second high temperature zone may be preheated.

[0095] The reservoir may be in fluid communication with the second feed zone and the second high temperature zone.

[0096] The passageway may connect the reservoir to the second feed zone. In use, the liquid aerosol-forming substrate may be transported from the reservoir to the feed zone via the passageway. In use, the liquid aerosol-forming substrate may be transported from the reservoir to the second high temperature zone and then to the feed zone via the passageway.

[0097] The cartridge may include a second passage, for example a second narrowed passage. The second passage may connect the reservoir to the second feed zone. In use, the liquid aerosol-forming substrate may be transported from the reservoir to the feed zone via the second passage. In use, the liquid aerosol-forming substrate may be transported from the reservoir to the second high temperature zone and then to the feed zone via the second passage. The wall or second wall may form a periphery of the second passage.

[0098] Advantageously, the second passageway, or the second constricted passageway, may reduce heat dissipation from the heating element or the second hot zone or the second supply zone into the reservoir.

[0099] The cartridge may include first and second electrical contacts electrically connected to the heating element, the electrical contacts may include one or more of tin, silver, gold, copper, aluminum, steel such as stainless steel, phosphor bronze, tin alloyed with antimony, tin alloyed with zirconium, tin alloyed with bismuth, or tin alloyed with other components that enhance resistance to organic acids.

[0100] The electrical contacts may be configured to form an electrical connection with corresponding electrical contacts on the aerosol generation device when the cartridge is engaged with the aerosol generation device.

[0101] According to a second aspect of the present disclosure, there is provided an aerosol generation system. The system may comprise a cartridge. The cartridge may be a cartridge according to the present disclosure. The system may comprise an aerosol generation device. The aerosol generation device may comprise a power source.

[0102] The cartridge may be configured to engage and disengage from the aerosol generation device. The power source may be configured to provide power to the heating element. The power source may be configured to provide power to the heating element only when the cartridge is engaged with the aerosol generation device.

[0103] The aerosol generating device may include a controller, which may be configured to control the supply of power from the power source, and thus the heating of the heating element.

[0104] The power supply may be configured to supply power to the heating element for resistive heating of the heating element.The power supply may be configured to supply power to the heating element for inductive heating of the heating element.

[0105] The aerosol generating device may be configured to be engaged and disengaged from the cartridge via a snap-fit ​​connection, corresponding threads, or any other suitable means. The aerosol generating device may be configured to receive at least a portion of the cartridge. For example, the aerosol generating device may include a chamber configured to receive at least a portion of the cartridge.

[0106] The aerosol generating device may comprise an air inlet. The aerosol generating device may comprise an air outlet. When the aerosol generating device is engaged with the cartridge, the air outlet of the aerosol generating device may be in fluid communication with the air inlet of the cartridge.

[0107] The power source may be electrically connected to the first and second electrical contacts of the device. These first and second electrical contacts may be configured to form an electrical connection with corresponding first and second electrical contacts on the cartridge when the cartridge is engaged with the device. These corresponding first and second electrical contacts on the cartridge may be electrically connected to the heating element. Thus, the power source may be configured to provide power to the heating element by passing an electric current through the heating element.

[0108] The cartridge, or aerosol generator, may include an inductor, such as an induction coil. The heating element may be or include a susceptor material.

[0109] The power supply may be configured to pass a current, such as a high frequency alternating current, through the inductor such that the inductor generates a varying or oscillating electromagnetic field. This may then generate eddy currents and hysteresis losses in the susceptor material. This may heat the susceptor material. Thus, the power supply using the inductor may be configured to inductively heat the heating element.

[0110] Suitable susceptor materials include those previously described in connection with cartridges according to the present disclosure.

[0111] The inductor may be an induction coil. The inductor may be disposed within the cartridge. The inductor may be disposed around the heating element or around a portion of the heating element. For example, the inductor may be an induction coil and may be spiraled around the heating element or around a portion of the heating element.

[0112] The inductor may be electrically connected to electrical contacts on the cartridge. When the cartridge is engaged with the aerosol generating device, these electrical contacts may be electrically connected to corresponding electrical contacts on the device that are electrically connected to a power source of the device. When the cartridge is engaged with the device, the power source of the device may be configured to pass an electric current through the inductor to generate a varying electromagnetic field, thereby heating the susceptor material of the heating element.

[0113] An inductor, such as an induction coil, may be located within the aerosol generating device. The inductor may be electrically connected to a power supply of the aerosol generating device. The aerosol generating device may be configured to engage with the cartridge. For example, the device may include a chamber for receiving at least a portion of the cartridge. The induction coil may be disposed around at least a portion of the chamber. For example, the induction coil may be spiraled around at least a portion of the chamber. Thus, when the cartridge engages with the device, the induction coil may be disposed around or spiraled around the heating element or a portion of the heating element. When at least a portion of the cartridge is received within the chamber of the device, the power supply of the device may be configured to pass a current through the inductor to generate a fluctuating or oscillating electromagnetic field, thereby heating the susceptor material of the heating element.

[0114] As discussed above, induction heating may advantageously allow for the manufacture of simple, inexpensive, and robust cartridges. Additionally, induction heating may provide improved energy conversion compared to resistive heating.

[0115] The aerosol generating system may be a smoking system, an electrically operated smoking system. The aerosol generating system may be for recreational use. In use, the aerosol generating system may be suitable or configured to deliver nicotine to a user.

[0116] The aerosol generating system may be portable. The aerosol generating system may have a size comparable to a conventional cigar or cigarette. The smoking system may have a total length of between 30 mm and 200 mm. The smoking system may have an outer diameter of between 5 mm and 30 mm.

[0117] The term "aerosol" as used herein refers to a dispersion of solid particles, or liquid droplets, or a combination of solid particles and liquid droplets in a gas. Aerosols may be visible or invisible. Aerosols may include not only vapors of substances that are normally liquids or solids at room temperature, but also solid particles or liquid droplets, or a combination of solid particles and liquid droplets.

[0118] The term "aerosol-forming substrate" as used herein refers to a substrate capable of releasing a volatile compound capable of forming an aerosol. The volatile compound may be released by heating or burning the aerosol-forming substrate.

[0119] The aerosol-forming substrate may include a plurality of compounds. The compounds may have different boiling points. For example, the aerosol-forming substrate may include a first compound having a first boiling point at atmospheric pressure and a second compound having a second boiling point at atmospheric pressure, the first boiling point being higher than the second boiling point.

[0120] The aerosol-forming substrate may include an aerosol former. As used herein, "aerosol former" refers to any suitable compound or mixture of compounds that facilitates the formation of a stable aerosol that is substantially resistant to thermal decomposition when used, for example, at the operating temperature of the system. Suitable aerosol formers are well known in the art and include, but are not limited to, polyhydric alcohols (such as triethylene glycol, 1,3-butanediol, glycerin, etc.), esters of polyhydric alcohols (such as glycerol monoacetate, diacetate, or triacetate, etc.), and aliphatic esters of mono-, di-, or polycarboxylic acids (such as dimethyl dodecanedioate, dimethyl tetradecanedioate, etc.).

[0121] The aerosol-forming substrate may comprise nicotine. The aerosol-forming substrate may comprise water. The aerosol-forming substrate may comprise glycerin, also called glycerin, which has a higher boiling point than nicotine. The aerosol-forming substrate may comprise plant-derived material. The aerosol-forming substrate may comprise homogenized plant-derived material. The aerosol-forming substrate may comprise tobacco. The aerosol-forming substrate may comprise tobacco-containing material. The tobacco-containing material may contain volatile tobacco flavour compounds. These compounds may be released from the aerosol-forming substrate upon heating. The aerosol-forming substrate may comprise homogenized tobacco material. The aerosol-forming substrate may comprise other additives and ingredients such as flavourants.

[0122] As used herein, the term "liquid aerosol-forming substrate" is used to refer to an aerosol-forming substrate in a condensed form. Thus, a "liquid aerosol-forming substrate" may be or may include one or more of a liquid, a gel, or a paste. If the liquid aerosol-forming substrate is or includes a gel or paste, the gel or paste may flow upon heating. For example, the gel or paste may flow upon heating to a temperature of less than 50, 75, 100, 150, or 200 degrees Celsius.

[0123] The terms hot zone and feed zone may be used interchangeably with first space and second space, respectively.

[0124] As used herein, the term "reservoir" may be used to refer to a reservoir for storing a liquid aerosol-forming substrate or a reservoir of a liquid aerosol-forming substrate, unless expressly stated otherwise. The term "reservoir" may be used to refer to a reservoir for storing a flowable liquid aerosol-forming substrate or a reservoir of a flowable liquid aerosol-forming substrate, unless expressly stated otherwise.

[0125] The present invention is defined in the claims. However, below is provided a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of any other example, embodiment, or aspect described herein.

[0126] Example 1 1. A cartridge for use in an aerosol generation system, comprising: a reservoir of liquid aerosol-forming substrate; a heating element for heating the liquid aerosol-forming substrate from the reservoir; a wall; a first space adjacent to the heating element and between the wall and the heating element defines a high temperature zone; a second space adjacent the heating element forming a feed zone; The reservoir is in fluid communication with the feed zone and the high temperature zone. Example 2 A cartridge according to Example 1, wherein in use, the hot zone is heated to a first temperature and the feed zone is heated to a second temperature, the first temperature being greater than the second temperature. Example 3 The cartridge according to example 2, wherein the first temperature is at least 5 degrees Celsius higher than the second temperature. Example 4 A cartridge according to any of Examples 1 to 3, wherein the wall is located within the reservoir. Example 5 A cartridge according to any of Examples 1-4, wherein the wall insulates the high temperature zone from the reservoir. Example 6 A cartridge according to any of Examples 1-5, wherein the wall insulates the feed zone from the reservoir to a lesser extent than the wall insulates the hot zone from the reservoir. Example 7 A cartridge according to any of Examples 1 to 6, wherein in use the liquid aerosol-forming substrate is transported from the reservoir towards the heating element via the delivery zone. Example 8 A cartridge according to any of Examples 1 to 7, wherein in use the liquid aerosol-forming substrate is transported from the reservoir to the hot zone via the feed zone. Example 9 The cartridge according to any of Examples 1 to 8, wherein the cartridge comprises an air inlet and an air outlet, and an airflow path defined between the air inlet and the air outlet. Example 10 A cartridge according to example 9, wherein air drawn from the air inlet to the air outlet flows across, past or through the heating element. Example 11 The cartridge according to example 9 or 10, wherein the heating element surrounds a portion of the airflow path. Example 12 The cartridge according to any one of Examples 1 to 11, wherein the heating element includes a first portion and a second portion. Example 13 The cartridge according to example 12, wherein the first portion is configured to be heated to a higher temperature than the second portion. Example 14 14. The cartridge according to example 12 or 13, wherein the first portion has a first electrical resistance and the second portion has a second electrical resistance, the first electrical resistance being greater than the second electrical resistance. Example 15 15. The cartridge according to any of Examples 12-14, wherein the second portion includes a folded portion in contact with itself. Example 16 The cartridge according to any of Examples 12-15, wherein the first portion includes one or more of a curve, fold, wave, and undulation. Example 17 The cartridge according to any of Examples 12-16, wherein the first portion is positioned closer to the high temperature zone than the second portion. Example 18 The cartridge according to any of Examples 12-17, wherein the second portion is positioned closer to the feed zone than the first portion. Example 19 A cartridge according to any of Examples 1 to 18, comprising a support for a heating element. Example 20 A cartridge according to example 19, wherein the wall forms a support. Example 21 The cartridge according to any of Examples 12-18, wherein the wall forms a support for the heating element, and a second portion of the heating element is in contact with the wall. Example 22 A cartridge according to any of Examples 1 to 21, wherein in use the liquid aerosol-forming substrate in the feed zone is vaporized and the liquid aerosol-forming substrate in the high temperature zone is vaporized. Example 23 The cartridge according to any one of Examples 1 to 22, wherein the second space is between the wall and the heating element. Example 24 A cartridge according to any of Examples 1-23, wherein the shortest distance between a wall and the heater through the high temperature zone is less than the shortest distance between a wall and the heater through the feed zone. Example 25 The cartridge according to any one of Examples 1 to 24, wherein the heating element is a mesh heating element. Example 26 A cartridge according to any of Examples 1-25, wherein the wall is configured to hold a liquid aerosol-forming substrate. Example 27 A cartridge according to any of Examples 1-26, wherein in use the liquid aerosol-forming substrate is allowed to pass from the reservoir, through the wall towards the heating element. Example 28 A cartridge according to any of Examples 1-27, wherein in use the liquid aerosol-forming substrate is allowed to pass from the reservoir, through the wall towards the hot zone. Example 29 The cartridge according to any of Examples 1-28, wherein the wall comprises a porous material. Example 30 The cartridge according to any of Examples 1 to 29, wherein the wall comprises a capillary retaining material. Example 31 A cartridge according to any of Examples 1 to 30, wherein the thermal conductivity of the wall is less than the thermal conductivity of the liquid aerosol-forming substrate. Example 32 The cartridge according to any of Examples 1-31, wherein the shortest distance between the high temperature zone and the heating element is equal to the shortest distance between the feed zone and the heating element. Example 33 An aerosol generating system comprising a cartridge according to any one of Examples 1 to 32. Example 34 An aerosol generating system according to Example 33, wherein the system comprises an aerosol generating device. Example 35 An aerosol generation system according to Example 34, wherein the cartridge is configured to engage and disengage from the aerosol generation device. Example 36 An aerosol generation system according to Examples 33, 34, or 45, wherein the aerosol generation system comprises a power source configured to supply power to the heating element to heat the heating element. Example 37 An aerosol generation system according to Example 34 or 35, wherein the aerosol generating device is configured to supply power to the heating element to heat the heating element. Example 38 An aerosol generation system according to Example 36 or 37, wherein the power source is configured to supply power to the heating element to resistively heat the heating element. Example 39 An aerosol generation system according to Example 36 or 37, wherein the power supply is configured to supply power to the heating element to inductively heat the heating element. Example 40 The aerosol generation system according to any one of Examples 33 to 39, wherein the aerosol generation system has a total length of 30 millimeters to 200 millimeters. Example 41 The aerosol generating system according to any one of Examples 33 to 40, wherein the aerosol generating system has an outer diameter of 5 millimeters to 30 millimeters. Example 42 The aerosol generating system according to any one of Examples 33 to 41, wherein the aerosol generating system is portable. Example 43 The aerosol generating system according to any one of Examples 33 to 42, wherein the aerosol generating system is a smoking system. The embodiments will now be further described with reference to the figures. [Brief description of the drawings]

[0127] [Figure 1] FIG. 1 shows a schematic cross-sectional view of a first aerosol generation system. [Diagram 2] FIG. 2 shows a schematic perspective view of a portion of a cartridge of a first aerosol generation system. [Diagram 3] FIG. 3 shows a schematic cross-sectional view of a second aerosol generation system. [Figure 4] FIG. 4 shows a schematic cross-sectional view of a third aerosol generation system. [Diagram 5] FIG. 5 shows a schematic cross-sectional view of a portion of a cartridge of a third aerosol generation system. [Figure 6] FIG. 6 shows a schematic perspective view of a portion of a cartridge of a third aerosol generation system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0128] 1 shows a schematic cross-sectional view of a first aerosol generation system 100. The aerosol generation system 100 comprises an aerosol generating device 150 and a cartridge 200. In this embodiment, the aerosol generation system 100 is an electrically operated smoking system.

[0129] The aerosol generating device 150 is portable and has a size comparable to a conventional cigar or cigarette. The device 150 includes a battery 152, such as a lithium iron phosphate battery, and a controller 154 electrically connected to the battery 152. The device 150 also includes two electrical contacts 156, 158 electrically connected to the battery 152. This electrical connection is a wired connection and is not shown in FIG.

[0130] The cartridge 200 comprises a first electrical contact 214 and a second electrical contact 216, an air inlet 202, an air outlet 204, a reservoir 303 of liquid aerosol-forming substrate, a heating element 304, and a wall 307. The air inlet 202 is in fluid communication with the air outlet 204. The heater assembly 300 is positioned downstream of the air inlet 202 and upstream of the air outlet 204. The first electrical contact 214 and the second electrical contact 216 are electrically connected to the heating element 304.

[0131] In this system 100, the liquid aerosol-forming substrate comprises approximately 74% by weight glycerin, 24% by weight propylene glycol, and 2% by weight nicotine, although any suitable substrate may be used. At atmospheric pressure, nicotine has a boiling point of approximately 247 degrees Celsius, glycerin has a boiling point of approximately 290 degrees Celsius, and propylene glycol has a boiling point of approximately 188 degrees Celsius. Thus, when this liquid aerosol-forming substrate is first heated to form an aerosol, some systems may undesirably vaporize an excessively large amount of propylene glycol (which has the lowest boiling point of the compounds forming the substrate). This may lead to an undesirable aerosol being delivered to the user, such as an aerosol containing a lower percentage of nicotine than desired. This may also undesirably change the relative percentages of the compounds in the substrate over a longer period of time. The present invention may eliminate or at least reduce these undesirable effects.

[0132] Heating element 304 is an electrically resistive mesh heating element. In this example, the mesh is formed from stainless steel, although any suitable material may be used. Heating element 304 covers the open end of reservoir 303 of liquid aerosol-forming substrate. The mesh heating element includes openings that are small enough to prevent the liquid aerosol-forming substrate from leaking out, but large enough to allow an adequate flow rate of vaporized liquid aerosol-forming substrate to pass through in use. In this example, the openings are substantially square and have side lengths of about 25 microns.

[0133] Cartridge 200 includes a hot zone 306 and a feed zone 308. A first space adjacent to heating element 304 and between wall 307 and heating element 304 forms hot zone 306. A second space adjacent heating element 304 forms feed zone 306. Reservoir 303 is in fluid communication with feed zone 308 and hot zone 306.

[0134] The walls 307 are formed from a non-porous, non-permeable material. In the embodiment shown in Figure 1, the walls 307 are formed from polyethylene terephthalate, although any suitable material may be used.

[0135] Wall 307 forms the periphery of a constricted passage 310 that connects reservoir 303 to feed zone 308. In the embodiment shown in Figure 1, the liquid aerosol-forming substrate from reservoir 303 must pass through constricted passage 310 and then feed zone 308 to reach hot zone 306.

[0136] The surface of wall 307 facing heating element 304 is not parallel to the heating surface of heating element 304. The surface of wall 307 facing heating element 304 tapers towards heating element 304 in the direction from feed zone 308 to hot zone 306. Thus, the minimum and average distances from heating element 304 to wall 307 through hot zone 306 are less than the minimum and average distances from heating element 304 to wall 307 through feed zone 308.

[0137] Hot zone 306 is more insulated from supply zone 308. For example, hot zone 306 is more insulated from reservoir 303 than supply zone 308. Thus, less heat is dissipated from hot zone 306 into reservoir 303 than from supply zone 308 into reservoir 303.

[0138] The wall 307 has a significantly lower thermal conductivity than the liquid aerosol-forming substrate. Thus, the wall 307 effectively insulates the hot zone 306 and the feed zone 308 from the reservoir 303 of the liquid aerosol-forming substrate. Due to the taper of the wall 307, the portion of the wall 307 in contact with the feed zone 308 is thinner than the portion of the wall 307 in contact with the hot zone 306. Thus, the wall 307 insulates the feed zone 308 from the reservoir 303 to a lesser extent than the wall insulates the hot zone 306 from the reservoir 303.

[0139] 1, the aerosol generation device 150 is engaged with a cartridge 200. In this embodiment, the cartridge 200 is engaged with the aerosol generation device 150 via threads 206 of the cartridge 200 mating with corresponding threads 162 of the aerosol generation device 150.

[0140] In use, the user draws on the air outlet 204 of the cartridge 200. At the same time, the user presses a button (not shown) on the aerosol generating device 150. Pressing the button sends a signal to the controller 154, which in turn provides power from the battery 152 to the heating element 304 via the device's electrical contacts 156, 158 and the cartridge's electrical contacts 214, 216. This causes a current to flow through the heating element 304, which in turn resistively heats it. In other embodiments, an airflow sensor or pressure sensor is located within the cartridge 200 and electrically connected to the controller 154. The airflow sensor or pressure sensor detects that the user is drawing on the air outlet 204 of the cartridge 200 and sends a signal to the controller 154 to provide power to the heating element 304. Thus, in these embodiments, the user does not need to press a button to heat the heating element 304.

[0141] As the heating element 304 heats, the temperatures of the feed zone 308 and the hot zone 306 increase. The hot zone 306 increases in temperature at a faster rate than the feed zone 308. Both the feed zone 308 and the hot zone 306 reach a temperature at which at least one compound of the liquid aerosol-forming substrate vaporizes. As the heating element 304 heats, a hot zone - the hot zone - and a cold zone - the feed zone - are created. Specifically, the hot zone 306 heats to a temperature approximately 30 degrees Celsius higher than the feed zone 308. Several factors contribute to this temperature difference.

[0142] In the embodiment shown in Fig. 1, the liquid aerosol-forming substrate in the reservoir 303 must flow through a narrowed passage 310 and then through the feed zone 308 to reach the high temperature zone 306. Thus, as the liquid aerosol-forming substrate in the high temperature zone 306 vaporizes, the liquid aerosol-forming substrate from the feed zone 308 replaces it. Thus, a pre-heated liquid aerosol-forming substrate replaces the vaporized liquid aerosol-forming substrate from the high temperature zone 306. In contrast, as the liquid aerosol-forming substrate in the feed zone 308 vaporizes, the liquid aerosol-forming substrate from the reservoir 303 replaces it. Thus, the liquid aerosol-forming substrate replacing the vaporized liquid aerosol-forming substrate from the feed zone 308 is not pre-heated, or at least is pre-heated to a lesser extent than the liquid aerosol-forming substrate replacing the vaporized liquid aerosol-forming substrate from the high temperature zone 306. This increases the temperature difference between the hot zone 306 and the feed zone 308 .

[0143] The creation of hot and cold regions allows compounds of the liquid aerosol-forming substrate having high and low boiling points to be vaporized simultaneously in a more favorable ratio and at a more favorable rate.

[0144] As a user draws on the air outlet 204 of the cartridge 200, air is drawn into the air inlet 202. The air then travels across the heating element 304 toward the air outlet 204. The air flow entrains vapor that is formed by the heating element 304 heating the liquid aerosol-forming substrate in the hot zone 306 and feed zone 308. The entrained vapor then cools and condenses to form an aerosol. The aerosol is then delivered to the user via the air outlet 204. Arrows are used in FIG. 1 to indicate the direction of the air flow as a user draws on the air outlet 204.

[0145] Figure 2 shows a schematic perspective view of a portion of the cartridge. Specifically, Figure 2 shows the reservoir 303, the heating element 304, and the wall 307. In Figure 2, an enlarged view of a portion of the heating element 304 is shown. This shows the structure of the mesh heating element.

[0146] 3 shows a schematic cross-sectional view of a second aerosol generation system 400. The aerosol generation system 400 comprises an aerosol generating device 450 and a cartridge 500. In this embodiment, the aerosol generation system 400 is an electrically operated smoking system.

[0147] The aerosol generating device 450 is portable and has a size comparable to a conventional cigar or cigarette. The device 450 includes a battery 452, such as a lithium iron phosphate battery, and a controller 454 electrically connected to the battery 452. The device 450 also includes an induction coil 456 electrically connected to the battery 452. The device 450 also includes an air inlet 458 and an air outlet 460 in fluid communication with the air inlet 458.

[0148] The cartridge 500 comprises a reservoir 303 of liquid aerosol-forming substrate, a heating element 304, a wall 307, a hot zone 306, a feed zone 308 and a narrowed passage 310. The reservoir 303 of liquid aerosol-forming substrate, the heating element 304, the wall 307, the hot zone 306, the feed zone 308 and the narrowed passage 310 are all the same as shown and described in relation to the first embodiment shown in Figure 1. However, the heating element 304 in the embodiment shown in Figure 3 is configured to be inductively heated.

[0149] The cartridge 500 comprises an air inlet 502 and an air outlet 504. The air inlet 502 is in fluid communication with the air outlet 504. The heating element 304 is positioned downstream of the air inlet 502 and upstream of the air outlet 504. As shown in Figure 3, when the cartridge 500 is engaged with an aerosol generating device 450, the air outlet 460 of the device 450 is adjacent to the air inlet 502 of the cartridge 500. Thus, in use, when a user draws on the air outlet 504 of the cartridge 500, air flows through the air inlet 458 of the device 450, then through the air outlet 460 of the device 450, then through the air inlet 502 of the cartridge 500, then through the heating element 304, and then through the air outlet 504 of the cartridge 500.

[0150] 3, the cartridge 500 is engaged with the aerosol generation device 450. In this embodiment, the cartridge 500 engages with the aerosol generation device 450 via openings 506, 508 that form a snap-fit ​​connection with corresponding protrusions 462, 464 on the aerosol generation device 450.

[0151] 3, the heating element 304 is configured to be inductively heated rather than resistively heated, and therefore the stainless steel material of the heating element 304 acts as a susceptor material, although any suitable susceptor material may be used, among others.

[0152] In use, a user draws on the air outlet 504 of the cartridge 500. At the same time, the user presses a button (not shown) on the aerosol generating device 450. Pressing the button sends a signal to the controller 454, which causes the battery 452 to supply high frequency current to the induction coil 456. This causes the induction coil 456 to generate a fluctuating or oscillating electromagnetic field. The heating element 304 is positioned within this magnetic field. This fluctuating electromagnetic field thus generates eddy currents and hysteresis losses in the heating element 304. Thus, the heating element 304 is inductively heated. In another embodiment, an airflow or pressure sensor is disposed within the device 450 and electrically connected to the controller 454. The airflow or pressure sensor detects that the user is drawing on the air outlet 504 of the cartridge 500 and sends a signal to the controller 454 to supply high frequency current to the induction coil 456, thereby heating the heating element 304. Thus, in these embodiments, the user does not need to press a button to heat first heating element 604 and second heating element 605 .

[0153] As the heating element 304 heats, the temperatures of the feed zone 308 and the hot zone 306 increase. The hot zone 306 increases in temperature at a faster rate than the feed zone 308. Both the feed zone 308 and the hot zone 306 reach a temperature at which at least one compound of the liquid aerosol-forming substrate vaporizes. As the heating element 304 heats, a hot zone - the hot zone - and a cold zone - the feed zone - are created. Specifically, the hot zone 306 heats to a temperature approximately 30 degrees Celsius higher than the feed zone 308. Several factors contribute to this temperature difference.

[0154] Due to the taper of the wall 307 , the hot zone 306 is, on average, closer to the heating element 304 than the feed zone 308 .

[0155] Hot zone 306 is more insulated from supply zone 308. For example, hot zone 306 is more insulated from reservoir 303 than supply zone 308. Thus, less heat is dissipated from hot zone 306 into reservoir 303 than from supply zone 308 into reservoir 303.

[0156] In the embodiment shown in Fig. 3, as in the embodiment shown in Fig. 1, the liquid aerosol-forming substrate in the reservoir 303 must flow through the narrowed passage 310 and then through the feed zone 308 to reach the high temperature zone 306. Thus, as the liquid aerosol-forming substrate in the high temperature zone 306 vaporizes, the liquid aerosol-forming substrate from the feed zone 308 replaces it. Thus, the preheated liquid aerosol-forming substrate replaces the vaporized liquid aerosol-forming substrate from the high temperature zone 306. In contrast, as the liquid aerosol-forming substrate in the feed zone 308 vaporizes, the liquid aerosol-forming substrate from the reservoir 303 replaces it. Thus, the liquid aerosol-forming substrate replacing the vaporized liquid aerosol-forming substrate from the feed zone 308 is not preheated, or at least is preheated to a lesser extent than the liquid aerosol-forming substrate replacing the vaporized liquid aerosol-forming substrate from the high temperature zone 306. This increases the temperature difference between the hot zone 306 and the feed zone 308 .

[0157] The creation of hot and cold regions allows compounds of the liquid aerosol-forming substrate having high and low boiling points to be vaporized simultaneously in a more favorable ratio and at a more favorable rate.

[0158] As a user puffs on the air outlet 504 of the cartridge 500, air is drawn into the air inlet 458 of the device 450, then through the air outlet 460 of the device 450, and then through the air inlet 502 of the cartridge 500. The air then travels past the heating element 304 toward the air outlet 504. The air stream entrains vapor formed by heating the liquid aerosol-forming substrate by the heating element 304. The entrained vapor then cools and condenses to form an aerosol. The aerosol is then delivered to the user via the air outlet 504.

[0159] 4 shows a schematic cross-sectional view of a third aerosol generation system 600. The aerosol generation system 600 comprises an aerosol generating device 650 and a cartridge 700. In this embodiment, the aerosol generation system 600 is an electrically operated smoking system.

[0160] The aerosol generating device 650 is portable and has a size comparable to a conventional cigar or cigarette. The device 650 includes a battery 652, such as a lithium iron phosphate battery, and a controller 654 electrically connected to the battery 652. The device 650 also includes two electrical contacts 656, 658 electrically connected to the battery 652. This electrical connection is a wired connection and is not shown in FIG.

[0161] The cartridge 700 comprises a first electrical contact 714 and a second electrical contact 716, an air inlet 702, an air outlet 704, a reservoir of liquid aerosol-forming substrate 803, a heating element 804, and a wall 807. The air inlet 702 is in fluid communication with the air outlet 704. The heating element 804 is positioned downstream of the air inlet 702 and upstream of the air outlet 704. The first electrical contact 714 and the second electrical contact 716 are electrically connected to the heating element 804.

[0162] In this system 600, the liquid aerosol-forming substrate comprises about 98% by weight glycerin and 2% by weight nicotine, although any suitable substrate may be used. At atmospheric pressure, nicotine has a boiling point of about 247 degrees Celsius, and glycerin has a boiling point of about 290 degrees Celsius. Thus, when this liquid aerosol-forming substrate is first heated to form an aerosol, some systems may undesirably vaporize an excessively large amount of nicotine (which has the lowest boiling point of the compounds forming the substrate). This may lead to an undesirable aerosol being delivered to the user. This may also undesirably change the relative proportions of the compounds in the substrate over a longer period of time. The present invention may eliminate or at least reduce these undesirable effects.

[0163] Heating element 804 is an electrically resistive mesh heating element. In this example, the mesh is formed from stainless steel, although any suitable material may be used. Heating element 804 substantially completely surrounds the airflow path from air inlet 702 to air outlet 704. Specifically, heating element 804 surrounds the airflow path by approximately 355 degrees. The mesh heating element includes openings that are small enough to prevent liquid aerosol-forming substrate from escaping, but large enough to allow an adequate flow rate of vaporized liquid aerosol-forming substrate to pass through in use. In this example, the openings are substantially square and have a side length of approximately 25 microns.

[0164] Cartridge 700 includes multiple high temperature zones and multiple feed zones, which will now be described in more detail with reference to FIG.

[0165] Figure 5 is a schematic cross-sectional view of a portion of a cartridge of a third aerosol generation system. The cross-sectional view shown in Figure 5 is perpendicular to the cross-sectional view shown in Figure 4. Specifically, the view shown in Figure 5 is the cross-sectional view indicated by line AA in Figure 4.

[0166] Figure 5 shows a reservoir 803 of liquid aerosol-forming substrate bounded by a container 805. Figure 5 also shows a heating element 804, a first hot zone 806, a second hot zone 816, a third hot zone 826, a first feed zone 808, a second feed zone 818, a third feed zone 828, a fourth feed zone 838, and a wall 807 forming the periphery of a first constricted passage 810, a second constricted passage 820, a third constricted passage 830, and a fourth constricted passage 840. The reservoir 803 of liquid aerosol-forming substrate is in fluid communication with all of the feed zones and the hot zone.

[0167] In use, the liquid aerosol-forming substrate may flow from the reservoir 803 through the first constricted passage 810, then through the first feed zone 808, and then to the first high temperature zone 806. The first feed zone 808 is adjacent to the heating element 804 and disposed between the heating element 804 and the wall 807. The first high temperature zone 806 is adjacent to the heating element 804 and disposed between the heating element 804 and the wall 804. The first feed zone 808 is adjacent to the first high temperature zone 806. A portion 8041 of the heating element 804 adjacent to the first feed zone 808 and the first high temperature zone 806 is curved such that the minimum distance from the heating element 804 to the wall 807 through the first high temperature zone 806 is less than the minimum distance from the heating element 804 to the wall 807 through the first feed zone 808. This allows the first high temperature zone 806 to be heated to a higher temperature than the first feed zone 808 .

[0168] In use, the liquid aerosol-forming substrate may flow from the reservoir 803 through the second narrowed passage 820, then through the second feed zone 818, and then to the second high temperature zone 816. The second feed zone 818 is adjacent to the heating element 804 and is disposed between the heating element 804 and the wall 807. The second high temperature zone 816 is adjacent to the heating element 804 and is disposed between the heating element 804 and the wall 804. The second feed zone 818 is adjacent to the second high temperature zone 816. A portion 8042 of the heating element 804 adjacent to the second high temperature zone 816 includes some undulations. These undulations increase the volume and surface area of ​​the heating element 804 adjacent to the second high temperature zone 816. This allows the second high temperature zone 816 to be heated to a higher temperature than the second feed zone 818.

[0169] In use, the liquid aerosol-forming substrate may flow from the reservoir 803, through the third constricted passage 830, then through the third feed zone 828, and then to the third hot zone 826. The third feed zone 828 is adjacent to the heating element 804 and disposed between the heating element 804 and the wall 807. The third hot zone 826 is adjacent to the heating element 804 and disposed between the heating element 804 and the wall 804. The third feed zone 828 is adjacent to the third hot zone 826. A portion 8043 of the heating element 804 adjacent to the third feed zone 828 and the third hot zone 826 varies in thickness. Specifically, the thickness varies such that the minimum thickness of the heating element 804 adjacent to the third hot zone 826 is approximately 50% less than the minimum thickness of the heating element 804 adjacent to the third feed zone 828. The thinned portions of the heating element 804 may have increased electrical resistance and therefore may be resistively heated to higher temperatures in use, which may allow the third high temperature zone 826 to be heated to a higher temperature than the third supply zone 828.

[0170] Cartridge wall 807 forms four supports for heating element 804. Sections 851, 852, 853, 854 of heating element 804 each contact a support.

[0171] Each section 851, 852, 853, 854 of the heating element 804 that contacts the support is folded over on itself. Thus, each folded section 851, 852, 853, 854 has a lower electrical resistance and heats up to a lower temperature than if each section 851, 852, 853, 854 was not folded over on itself. Thus, each section 851, 852, 853, 854 of the heating element 804 dissipates less heat into the reservoir 803 of the liquid aerosol-forming substrate.

[0172] The wall 807 is formed from a porous material. In the embodiment shown in FIG. 5, the wall 807 is formed from a porous ceramic material, in particular alumina, although any suitable material may be used. Thus, the liquid aerosol-forming substrate may pass from the reservoir 803 through the wall 807 into one of the feed zones 808, 818, 828 or the hot zones 806, 816, 826. This may help to prevent either the feed zones 808, 818, 828 or the hot zones 806, 816, 826 from drying out as the liquid aerosol-forming substrate is vaporized. The porosity and pore size distribution of the wall 807 are selected to allow an adequate flow rate of liquid from the reservoir 803 to flow through the wall 807 in use. In the embodiment shown in FIG. 5, the porosity of the wall 807 is approximately 50%. As used herein, the term "porosity" refers to a measure, expressed as a percentage, of the volume of the accessible pores, or empty space, of the wall divided by the total volume of the wall. The porosity herein was measured by mercury porosimetry. Pores of different shapes and sizes may be present in the wall 807. In the example shown in FIG. 5, the pores in the wall 807 have an average pore size of about 30 microns. The pore size distribution is defined as the statistical distribution of the diameter of the largest sphere that can fit inside the pore at a given point. The term "average pore size" as used herein refers to the average of this pore size distribution. The pore sizes referred to herein were obtained using mercury porosimetry.

[0173] Despite the porosity of the wall 807, a substantial proportion of the liquid aerosol-forming substrate reaching the hot zones 806, 816, 826 from the reservoir 803 travels through the feed zones 808, 818, 828. Thus, most of the liquid aerosol-forming substrate reaching the hot zones 806, 816, 826 is preheated. This may help to increase or maintain the temperature difference of the liquid aerosol-forming substrate in the hot zones 806, 816, 826 compared to the feed zones 808, 818, 828.

[0174] The wall 807 has a significantly lower thermal conductivity than the liquid aerosol-forming substrate, and therefore effectively insulates the hot zones 806, 816, 826 and the feed zones 808, 818, 828 from the reservoir 803 of the liquid aerosol-forming substrate.

[0175] Figure 6 shows a schematic perspective view of a portion of the cartridge shown in Figure 5. Figure 6 shows a reservoir 803 of liquid aerosol-forming substrate, a container 805, a heating element 804, a wall 807, and one of the supports 809 previously described.

[0176] 4, the aerosol generation device 650 is engaged with the cartridge 700. In this embodiment, the cartridge 700 is engaged with the aerosol generation device 650 via threads 706 of the cartridge 700 mating with corresponding threads 662 of the aerosol generation device 650.

[0177] In use, a user draws on the air outlet 704 of the cartridge 700. At the same time, the user presses a button (not shown) on the aerosol generating device 650. Pressing the button sends a signal to the controller 654, which in turn provides power to the heating element 804 from the battery 652 via the device's electrical contacts 656, 658 and the cartridge's electrical contacts 714, 716. This causes a current to flow through the heating element 804, which in turn resistively heats it. In other embodiments, an airflow or pressure sensor is disposed within the cartridge 700 and electrically connected to the controller 654. The airflow or pressure sensor detects that the user is drawing on the air outlet 704 of the cartridge 700 and sends a signal to the controller 654 to provide power to the heating element 804. Thus, in these embodiments, the user does not need to press a button to heat the heating element 804.

[0178] As the heating element 804 heats, the temperature of the feed zones 808, 818, 828 and the hot zones 806, 816, 826 increases. The feed zones 808, 818, 828 and the hot zones 806, 816, 826 all reach a temperature at which at least one compound of the liquid aerosol-forming substrate vaporizes. As the heating element 804 heats, a hot area - the hot zone - and a cold area - the feed zone - are created.

[0179] The creation of hot and cold regions can allow compounds of the liquid aerosol-forming substrate having high and low boiling points to simultaneously vaporize in a more favorable ratio and at a more favorable rate.

[0180] As a user puffs on the air outlet 704 of the cartridge 700, air is drawn into the air inlet 702. The air then travels across the heating element 804 toward the air outlet 704. The air flow entrains vapor formed by heating the liquid aerosol-forming substrate by the heating element 804. The entrained vapor then cools and condenses to form an aerosol. The aerosol is then delivered to the user via the air outlet 704. In FIG. 1, the arrows indicate the direction of air flow as the user puffs on the air outlet 704.

[0181] The cartridge described herein achieves the creation of hot and cold regions within the liquid aerosol-forming substrate. Advantageously, this can improve the control of vaporization of different compounds of the liquid aerosol-forming substrate. This can facilitate liquid aerosol-forming substrate compounds with high and low boiling points to be vaporized simultaneously in a more favorable ratio and at a more favorable rate. This can allow for the generation of aerosols with more desirable compositions, and more consistent generation of aerosols with desirable compositions.

[0182] For the purposes of this specification and the appended claims, unless otherwise indicated, all numbers expressing amounts, quantities, percentages, and the like, should be understood in all instances as being modified by the term "about." Also, all ranges include the maximum and minimum points disclosed, and include any intermediate ranges therein, which may or may not be specifically recited herein. Thus, in this context, the number A is understood as A±10%. Within this context, the number A may be considered to include values ​​that are within the general standard error for the measurement of the property that the number A modifies. The number A may, in some instances used in the appended claims, deviate by the percentages recited above, provided that the amount by which A deviates does not materially affect the basic and novel properties of the claimed invention. Also, all ranges include the maximum and minimum points disclosed, and include any intermediate ranges therein, which may or may not be specifically recited herein.

Claims

1. 1. A cartridge for use in an aerosol generation system, comprising: a reservoir for a liquid aerosol-forming substrate; a heating element for heating the liquid aerosol-forming substrate from said reservoir; a wall comprising a porous material; a first space adjacent to the heating element and between the wall and the heating element defines a high temperature zone; a second space adjacent to the heating element forms a feed zone; the reservoir is in fluid communication with the feed zone and the high temperature zone; At least a portion of the wall is positioned between the high temperature zone and the reservoir; the wall is in contact with the hot zone and the reservoir; A cartridge wherein a portion of the wall in contact with the feed zone is thinner than a portion of the wall in contact with the high temperature zone.

2. 2. The cartridge of claim 1, wherein, in use, the high temperature zone is heated to a first temperature and the feed zone is heated to a second temperature, the first temperature being greater than the second temperature.

3. A cartridge according to any preceding claim, wherein the wall insulates the feed zone from the reservoir to a lesser extent than the wall insulates the hot zone from the reservoir.

4. 4. A cartridge according to any preceding claim, wherein the cartridge includes an air inlet and an air outlet, an airflow path being defined between the air inlet and the air outlet, and the heating element surrounding a portion of the airflow path.

5. The cartridge of any one of claims 1 to 4, wherein the heating element comprises a first portion and a second portion, and the first portion is configured to be heated to a higher temperature than the second portion.

6. 6. The cartridge of claim 5, wherein the first portion is positioned closer to the high temperature zone than the second portion, or the second portion is positioned closer to the feed zone than the first portion, or both the first portion is positioned closer to the high temperature zone than the second portion and the second portion is positioned closer to the feed zone than the first portion.

7. A cartridge according to any preceding claim, wherein the shortest distance between the wall and the heating element through the high temperature zone is less than the shortest distance between the wall and the heating element through the supply zone.

8. A cartridge according to any preceding claim, wherein at least a portion of the wall is located between the supply zone and the reservoir.

9. A cartridge according to any preceding claim, wherein the feed zone is adjacent to an opening in the wall.

10. A cartridge according to any preceding claim, wherein the cartridge comprises a constricted passageway connecting the reservoir to the supply zone.

11. A cartridge according to any preceding claim, comprising a support for the heating element.

12. The cartridge according to any one of claims 1 to 11, wherein the second space is between the wall and the heating element.

13. A cartridge according to any preceding claim, wherein the thermal conductivity of the wall is less than the thermal conductivity of the liquid aerosol-forming substrate.

14. An aerosol generating system comprising a cartridge according to any one of claims 1 to 13.

Images