RU2850824C1 - Heater in an assembly and aerosol generating system with such a heater in an assembly - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: heater assembly (300) is provided for use in an aerosol generating system (100). The heater assembly (300) includes a component (302) for storing a liquid substrate that forms an aerosol and a heating element (304). The heating element (304) comprises a first part (306) and a second part (308). The first part (306) of the heating element (304) is integrated into the component (302) for storing the liquid substrate forming the aerosol, and the second part (308) of the heating element (304) is not integrated into the component (302) for storing the liquid aerosol-forming substrate. An aerosol-generating system (100) containing the heater assembly (300) is also provided.

EFFECT: control of the evaporation of various compounds of the liquid substrate forming the aerosol in cases where these compounds have different boiling points.

12 cl, 6 dwg

Description

The present invention relates to a heater assembly. In particular, the present invention relates to a heater assembly for use in an aerosol-generating system. The present invention also relates to an aerosol-generating system comprising the heater assembly.

In many known aerosol-generating systems, the liquid substrate that forms the aerosol is heated and evaporated, producing vapor. The vapor cools and condenses, forming an aerosol. In some aerosol-generating systems, such as electrically heated smoking systems, this aerosol is then inhaled by the user.

Typically, the liquid aerosol-forming substrate contains several compounds that evaporate when heated. These compounds may have different boiling points. For example, a liquid aerosol-forming substrate might contain nicotine (with a boiling point of approximately 247 degrees Celsius at atmospheric pressure) and glycerol (with a boiling point of approximately 290 degrees Celsius at atmospheric pressure).

When a liquid aerosol-forming substrate containing compounds with different boiling points is heated, the compounds with lower boiling points may evaporate before those with higher boiling points. Alternatively, or additionally, the compounds with lower boiling points may evaporate at a faster rate than those with higher boiling points.

This may be undesirable, as it may limit interactions and combinations between different compounds. For example, a liquid aerosol-forming substrate may contain a nicotine compound and an organic acid compound, with these compounds having different boiling points. Both of these compounds can evaporate. Nicotine in the liquid aerosol-forming substrate may, upon evaporation, form freebase nicotine. However, it may be desirable to generate an aerosol with a nicotine salt rather than freebase nicotine. To form this nicotine salt, freebase nicotine can be protonated by the vaporized organic acid. However, this protonation may be limited if the organic acid does not evaporate until after the nicotine has evaporated, or if it evaporates more slowly than required to protonate a suitable proportion of freebase nicotine.

Furthermore, the faster evaporation of some compounds from the aerosol-forming substrate than others may undesirably cause the properties of the generated aerosol to change over time, for example, during a puff on an aerosol-generating system. This may be because, at the beginning of a puff, when the heating element is activated and its temperature rises, the liquid aerosol-forming substrate near the heating element may reach a first temperature at which the first compound with a lower boiling point evaporates, while the second compound with a higher boiling point does not evaporate. Then, later in the puff, the liquid aerosol-forming substrate near the heating element may reach a second temperature at which the second compound with a higher boiling point evaporates. However, at this point, most of the first compound in the liquid aerosol-forming substrate near the heating element may have already evaporated. Thus, at the start of the puff, the generated aerosol may contain a higher proportion of the first compound, and later in the puff, the generated aerosol may contain a higher proportion of the second compound.

Alternatively, or additionally, the properties of the generated aerosol may change over the course of several puffs. This may occur when the compounds of the liquid aerosol-forming substrate do not evaporate at the proper rate. For example, the liquid aerosol-forming substrate may contain X percent by mass of a first compound and Y percent by mass of a second compound. If the liquid aerosol-forming substrate does not evaporate to form a vapor containing an X to Y mass ratio of the first compound to the second compound, the composition of the liquid aerosol-forming substrate may change as the vapor is generated. This, in turn, may lead to changes in the properties of the aerosol generated by the liquid aerosol-forming substrate.

The aim of the present invention is to control the evaporation of various compounds of a liquid substrate forming an aerosol in the case where these compounds have different boiling points.

According to an aspect of the present invention, a heater assembly is provided. The heater assembly may be suitable for use in an aerosol-generating system. The heater assembly may comprise a component for storing a liquid aerosol-forming substrate. The heating element may comprise a first portion. The heating element may comprise a second portion. The first portion of the heating element may be integrated into the component for storing the liquid aerosol-forming substrate. The second portion of the heating element may not be integrated into the component for storing the liquid aerosol-forming substrate.

The heater assembly may provide higher-temperature regions and lower-temperature regions within the aerosol-forming liquid substrate storage component. Alternatively, or additionally, the heater assembly may provide regions whose temperature increases at a faster rate and regions whose temperature increases at a slower rate within the aerosol-forming liquid substrate storage component.

Advantageously, the heater assembly can improve the control of the evaporation of various compounds in the liquid aerosol-forming substrate. The heater assembly can ensure the simultaneous evaporation of higher-boiling and lower-boiling liquid aerosol-forming substrate compounds at desired rates. The heater assembly can ensure the evaporation of higher-boiling and lower-boiling liquid aerosol-forming substrate compounds in more favorable proportions. The heater assembly can ensure the generation of an aerosol with a more desirable composition. The heater assembly can ensure more consistent generation of an aerosol with desired properties.

The heating element may comprise a third portion and a fourth portion. The third portion of the heating element may be integrated into the component for storing the liquid aerosol-forming substrate. The fourth portion may not be integrated into the component for storing the liquid aerosol-forming substrate.

This can advantageously create more regions of higher temperature and more regions of lower temperature in the aerosol-forming liquid substrate storage component. Alternatively, or additionally, it can provide more regions in which the temperature increases at a faster rate and more regions in which the temperature increases at a slower rate in the aerosol-forming liquid substrate storage component. This can lead to the simultaneous evaporation of compounds of the aerosol-forming liquid substrate with higher boiling points and lower boiling points at desired rates.

The second portion of the heating element may extend between the first portion and the third portion. That is, the second portion may connect the first portion to the third portion. The third portion may only be connected to the first portion through the second portion.

The third portion of the heating element may extend between the second portion and the fourth portion. That is, the third portion may connect the second portion to the fourth portion. The fourth portion may only be connected to the second portion via the third portion.

The heating element, or one or more than one, or all of the first part, second part, third part, and fourth part, may comprise an electrically resistive material. The heater assembly may be designed such that, during use, an electric current flows through said part or parts. This may result in resistive heating of said part or parts. Thus, said part or parts may be configured to provide resistive heating.

One, more than one, or all of the first portion, second portion, third portion, and fourth portion of the heating element may be formed from the same material.

One, more than one, or all of the first portion, second portion, third portion, and fourth portion of the heating element may have substantially the same electrical resistivity (measured in ohm-meters). For example, the first portion and second portion may have the same electrical resistivity. Alternatively, or additionally, the third portion and fourth portion of the heating element may have the same electrical resistivity. As used herein, the term "substantially the same electrical resistivity" is used to mean within 20, 10, or 5 percent of the specified electrical resistivity.

The heating element, or one or more than one, or all of the first part, second part, third part, and fourth part of the heating element, may comprise or be formed from any material with suitable electrical and mechanical properties, such as a suitable electrically resistive material. Suitable materials include, but are not limited to, semiconductors, such as doped ceramics, electrically conductive ceramics (such as, for example, molybdenum disilicide), carbon, graphite, metals, metal alloys, and composite materials made from a ceramic material and a metallic material. Such composite materials may comprise doped or undoped ceramics. Examples of suitable doped ceramics include doped silicon carbides. Examples of suitable metals include titanium, zirconium, tantalum, and platinum group metals. Examples of suitable metallic alloys include stainless steel, constantan, nickel-, cobalt-, chromium-, aluminum-, titanium-, zirconium-, hafnium-, niobium-, molybdenum-, tantalum-, tungsten-, tin-, gallium-, manganese-, and iron-based alloys, as well as nickel-, iron-, and cobalt-based superalloys, stainless steel, Timetal®, iron-aluminum-based alloys, and iron-, manganese-, and 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 optionally be embedded, encapsulated, or coated with the insulating material, or vice versa, depending on the energy transfer kinetics and the desired external physicochemical properties. The heating element may comprise an etched metal foil insulated between two layers of inert material. In this case, the inert material may comprise Kapton®, a foil composed entirely of polyimide or mica. Kapton® is a registered trademark of E.I. du Pont de Nemours and Company, 1007 Market Street, Wilmington, Delaware 198 98, United States of America.

The third and fourth parts may be configured for resistive heating. The third and fourth parts may comprise an electrically resistive material. The first and second parts may be configured for resistive heating. The first and second parts may comprise an electrically resistive material.

The heating element, or one or more than one, or all of the first part, second part, third part, and fourth part, may comprise a current-sensing material. The heater assembly may be designed such that said part or parts are inductively heated during use.

For example, the heater assembly may be configured for use in an aerosol-generating system comprising an inductor, such as an induction coil. The inductor may be located in an aerosol-generating device that includes a power supply. The device may be configured to engage the heater assembly or a cartridge comprising the heater assembly. Alternatively, the inductor may be located in a cartridge comprising the heater assembly. The cartridge may be configured to engage the aerosol-generating device that includes a power supply.

The power supply may be configured to provide alternating current through an inductor in the cartridge or an inductor in the device such that the inductor generates an oscillating electromagnetic field.

Alternating current can have any suitable frequency. Alternating current can be high-frequency alternating current. The term "high-frequency alternating current" can refer to frequencies from 100 kilohertz (kHz) to 30 megahertz (MHz). When the inductor is a tubular induction coil, the alternating current can have a frequency from 500 kilohertz (kHz) to 30 megahertz (MHz). If the inductor is a flat induction coil, the alternating current can have a frequency from 100 kilohertz (kHz) to 1 megahertz (MHz).

The heating element, or one or more than one, or all of the first part, second part, third part, and fourth part, may be located within the electromagnetic field generated by the inductor or otherwise exposed to it. This may result in eddy currents and hysteresis losses in the current-receiving material. This may cause heating of the current-receiving material. Thus, the power supply and inductor may be configured to inductively heat one or more than one, or all of the first part, second part, third part, and fourth part.

The current-collecting material may be or may comprise any material that can be inductively heated to a temperature sufficient to generate an aerosol from an aerosol-forming substrate. Preferred current-collecting materials can be heated to a temperature exceeding 50, 100, 150, 200, 250, 300, 350, or 400 degrees Celsius. Preferred current-collecting materials may comprise a metal or carbon, or both a metal and carbon. A preferred current-collecting material may comprise a ferromagnetic material, such as ferritic cast iron or ferromagnetic steel, or stainless steel. A suitable current-collecting element may be or comprise one or more of graphite, molybdenum, silicon carbide, stainless steel, niobium, and aluminum. Preferred current-collecting materials may comprise or be formed from 400-series stainless steels, such as Type 410, Type 420, or Type 430 stainless steel. Different materials will dissipate different amounts of energy when placed within electromagnetic fields of similar frequency and field strength. Therefore, current-collecting material parameters, such as material type and size, can be varied to achieve the desired power dissipation within a known electromagnetic field.

The third and fourth parts may be capable of induction heating. The third and fourth parts may comprise a current-collecting material. The first and second parts may be capable of induction heating. The first and second parts may comprise a current-collecting material.

Advantageously, an aerosol-generating system using induction heating eliminates the need for electrical contacts between the heater assembly and the aerosol-generating device. Furthermore, the heating element may not require electrical connections to other components. This can eliminate the need for solder or other bonding agents. A cartridge containing a heater assembly configured for induction heating can allow for the manufacture of a cartridge that is simple, inexpensive, and reliable. Cartridges are typically disposable items, manufactured in much larger quantities than the aerosol-generating devices they support. Consequently, reducing the cost of cartridges can lead to significant cost savings for manufacturers. Furthermore, induction heating can provide improved energy conversion compared to resistive heating. This is because induction heating may not incur power losses associated with electrical resistance in the connections between the resistive heating element and the power supply.

A heating element may have a length, width, and thickness. A heating element may comprise a strip of material. The strip may have a length, width, and thickness. The width may be perpendicular to the length. The thickness may be perpendicular to the length and width. The length may be greater than the width. The width may be greater than the thickness.

The cross-section or cross-sectional area of a heating element may vary. For example, the cross-section or cross-sectional area of a heating element may vary along the length of the heating element.

The heating element may extend between a first end and a second end. For example, the length of the heating element may extend between the first end and the second end. The heating element may have a first cross-sectional area at a first point between the first end and the second end. The heating element may have a second cross-sectional area at a second point between the first point and the second end. The heating element may have a third cross-sectional area at a third point between the second point and the second end. Each of the first cross-sectional area and the third cross-sectional area may be greater than or less than the second cross-sectional area. For example, the first cross-sectional area and the third cross-sectional area may be at least 10, 20, 50, 100, 200, or 500 percent greater than, or at least 10, 20, 30, 40, 50, 60, 70, or 80 percent less than, the second cross-sectional area. Thus, by observing how the cross-sectional area of the heating element changes from the first end to the second end of the heating element, the cross-sectional area of the heating element may decrease and then increase. Alternatively, or additionally, the cross-sectional area of the heating element may increase and then decrease.

Changing the cross-section or cross-sectional area of a heating element can cause different sections of the heating element to simultaneously reach different temperatures. For example, in a resistive heating element, a section of the heating element with a smaller cross-sectional area may have a higher resistance and thus be resistively heated to a higher temperature.

This can advantageously create regions of higher temperature and regions of lower temperature. Alternatively, or additionally, it can provide regions in which the temperature increases at a faster rate and regions in which the temperature increases at a slower rate within the aerosol-forming liquid substrate storage component. As explained above, this can lead to the simultaneous evaporation of compounds of the aerosol-forming liquid substrate with higher boiling points and lower boiling points at desired rates.

The minimum cross-sectional area along the length of the heating element may be at least 10 percent less than the maximum cross-sectional area along the length of the heating element. The minimum cross-sectional area along the length of the heating element may be at least 20, 40, 60, or 80 percent less than the maximum cross-sectional area along the length of the heating element.

The minimum cross-sectional area of the first portion of the heating element may be at least 10, 20, 40, 60, or 80 percent less than the maximum cross-sectional area of the second portion or the fourth portion. Alternatively or additionally, the minimum cross-sectional area of the third portion of the heating element may be at least 10, 20, 40, 60, or 80 percent less than the maximum cross-sectional area of the second portion or the fourth portion.

The width, thickness, or both the width and thickness of the heating element may vary along the length of the heating element.

A heating element may extend into and out of the aerosol-forming liquid substrate storage component. The heating element may comprise a strip of material that extends into and out of the aerosol-forming liquid substrate storage component. The heating element or strip may extend into and out of the aerosol-forming liquid substrate storage component along its length. Thus, when tracked along the length of the heating element or strip, the heating element or strip may alternately comprise portions integrated into the aerosol-forming liquid substrate storage component, such as a first portion and a third portion, and portions not integrated into the aerosol-forming liquid substrate storage component, such as a second portion and a fourth portion.

Mainly a heater assembly comprising

The heating element that enters and exits the aerosol-forming liquid substrate storage component can be relatively simple to manufacture.

The heating element may comprise one or more curved portions, wavy portions, bends, and corrugations. The first portion of the heating element may comprise one or more of a curved portion, a wavy portion, a bend, and a corrugation. The second portion of the heating element may comprise one or more of a curved portion, a wavy portion, a bend, and a corrugation. The third portion of the heating element may comprise one or more of a curved portion, a wavy portion, a bend, and a corrugation. The fourth portion of the heating element may comprise one or more of a curved portion, a wavy portion, a bend, and a corrugation. The fifth portion of the heating element may comprise one or more of a curved portion, a wavy portion, a bend, and a corrugation.

Preferably, curved portions, wavy portions, folds, and corrugations in a heating element can provide greater control over the locations of higher-temperature regions and lower-temperature regions. Alternatively, or in addition, curved portions, wavy portions, folds, and corrugations in a heating element can provide greater control over the temperature differences between higher-temperature regions and lower-temperature regions. For example, if a higher temperature is desired in a given region of a component for storing a liquid aerosol-forming substrate, the heating element may include a wavy portion or corrugation in that region. This can increase the volume or surface area of the heating element in that region and, consequently, increase the heat transferred from the heating element to that region.

A heating element may have a first end and a second end. The length of the heating element may extend from the first end to the second end. If the heating element does not extend directly from the first end to the second end, i.e., in a straight line, the heating element may be considered to contain one or more curved portions, wavy portions, folds, and corrugations.

A curved portion may refer to a gradual change in the direction of the heating element, such as a gradual change in the direction of the heating element between the first end and the second end. Thus, the curved portion may form an arc or a C-shape.

A bend can refer to a stepwise change in the direction of a heating element, such as a stepwise change in the direction of the heating element between the first end and the second end. Thus, a bend can form two sides of a polygon or a V-shape.

The wavy section may comprise multiple curved sections. For example, the wavy section may refer to a gradual change in the direction of the heating element in one direction, followed by a gradual change in the direction of the heating element in another, such as the opposite, direction. Thus, the wavy section may form a sine wave or an S-shape.

A corrugation may contain multiple folds. For example, a corrugation may refer to a stepped change in the direction of the heating element, followed by another stepped change in the direction of the heating element. Thus, the corrugation may form three sides of a rectangle, an M-shape, or an N-shape.

Advantageously, a heating element comprising one or more curved portions, wavy portions, folds, and corrugations can simplify the manufacture of a heater assembly comprising at least one portion of the heating element integrated into a component for storing a liquid aerosol-forming substrate and at least one portion not integrated into the component for storing the liquid aerosol-forming substrate. Furthermore, one or more of the curved portions, wavy portions, folds, and corrugations can enable the heating element to create regions of higher temperature. For example, a portion of the heating element integrated into a component for storing a liquid aerosol-forming substrate can have a highly curved S-shape. The region of the component for storing the liquid aerosol-forming substrate around this portion of the heating element can be heated to a higher temperature.

The heating element may comprise one or more irregular wavy sections and irregular corrugations along the length of the heating element. As used herein, the terms "irregular wavy sections" and "irregular corrugations" refer to wavy sections and corrugations that do not have a constant amplitude or frequency.

The amplitude of a wavy section or corrugation can be measured in a direction perpendicular to the length of the heating element. The amplitude of a wavy section or corrugation can be measured in the direction of the heating element's thickness. The amplitude can be defined as half the height difference between the peak or local maximum of the wavy section or corrugation and the trough or local minimum of the wavy section or corrugation.

The frequency of a ripple or corrugation refers to the number of repeating cycles per unit distance, such as per unit distance along the length of a heating element or between the first end and the second end of the heating element. This type of frequency is often referred to as spatial frequency. For example, if a heating element contains regular sinusoidal waves, the waves are considered ripples, and the frequency of these ripples is equal to 1 divided by the wavelength.

An example of a regular waveform is a predictable sine wave that has constant amplitude and frequency.

The frequency of the wavy portions or corrugations of the heating element may vary along the length of the heating element.

The amplitude of the wavy portions or corrugations of the heating element may vary along the length of the heating element.

Preferably, varying the amplitudes or frequencies, or both, can provide greater control over the locations of higher-temperature regions and lower-temperature regions. Alternatively, or additionally, varying the amplitudes or frequencies, or both, can provide greater control over the temperature differences between higher-temperature regions and lower-temperature regions.

The heater assembly may contain a reservoir for storing a liquid aerosol-forming substrate.

The component for storing the liquid aerosol-forming substrate may store or be configured to store the liquid aerosol-forming substrate.

The component for storing the liquid aerosol-forming substrate may be in fluid communication with the reservoir. In this case, when using heating element sections located further from the reservoir containing the liquid aerosol-forming substrate, or areas within the component for storing the liquid aerosol-forming substrate, the surrounding areas of these heating element sections may reach higher temperatures than sections or areas located closer to the reservoir containing the liquid aerosol-forming substrate. This is because more heat can be transferred, or heat can be transferred more quickly, from the heating element to the reservoir containing the liquid aerosol-forming substrate for heating element sections located closer to the reservoir containing the liquid aerosol-forming substrate.

Advantageously, the liquid aerosol-forming substrate storage component, which is in fluid communication with the reservoir, can provide for rapid and automatic replenishment of the liquid aerosol-forming substrate, which evaporates and is removed from the liquid aerosol-forming substrate storage component.

The component for storing the liquid aerosol-forming substrate may comprise or be a material impregnated with the liquid aerosol-forming substrate or a material capable of being impregnated with it. The component for storing the liquid aerosol-forming substrate may have a fibrous or spongy structure. The component for storing the liquid aerosol-forming substrate may comprise a capillary material. The component for storing the liquid aerosol-forming substrate may comprise a capillary bundle. For example, the component for storing the liquid aerosol-forming substrate may comprise one or more fibers, threads, and tubes with narrow channels.

The component for storing the liquid aerosol-forming substrate may contain a sponge-like or foam-like material. The structure of the component for storing the liquid aerosol-forming substrate may form several small channels or tubes through which the liquid can be transported by capillary action.

The component for storing the liquid aerosol-forming substrate may comprise any suitable material or combination of materials. Suitable materials include, but are not limited to: sponge material or foam, ceramic or graphite-based materials in the form of fibers or sintered powders, foamed metal or plastic material, fibrous material, for example, made from twisted or extruded fibers such as cellulose acetate, polyester or bonded polyolefin, polyethylene, terylene or polypropylene fibers, nylon fibers, or ceramics. The component for storing the liquid aerosol-forming substrate may comprise a ceramic material. The component for storing the liquid aerosol-forming substrate may have any suitable capillarity and porosity so that it can be used with different liquid aerosol-forming substrates having different physical properties.

The heating element may comprise a fifth portion, wherein the fifth portion is located in a reservoir. The term "reservoir," unless explicitly stated otherwise, may refer to a reservoir for storing a liquid aerosol-forming substrate or a reservoir containing a liquid aerosol-forming substrate. The term "reservoir," unless explicitly stated otherwise, may refer to a reservoir for storing a free-flowing liquid aerosol-forming substrate or a reservoir containing a free-flowing liquid aerosol-forming substrate.

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

The heating element can be perforated.

The heating element may be a mesh heating element. The heating element may comprise a mesh. The first portion, the second portion, or both the first and second portions may comprise perforations or a mesh. The third portion, the fourth portion, or both the third and fourth portions may comprise perforations or a mesh.

A mesh heating element, or a heating element containing a mesh, can provide a large surface area in contact with the liquid aerosol-forming substrate. This large surface area can ensure efficient evaporation of the liquid aerosol-forming substrate.

The heater assembly may include a second heating element. The features described with respect to the first heating element may be applied to the second heating element. Similarly, the features described with respect to portions of the first heating element may be applied to corresponding portions or sections of the second heating element. For example, one or more of the material and shape of the first heating element may be applied to the second heating element. Alternatively, the second heating element may have a shape or outline different from the heating element.

Advantageously, the second heating element can increase the rate of evaporation of the liquid aerosol-forming substrate in the liquid aerosol-forming substrate storage component. Furthermore, the distance between the first heating element and the second heating element can be selected to influence the temperature of the portion of the liquid aerosol-forming substrate storage component being used. For example, a portion of the liquid aerosol-forming substrate storage component in which the first heating element and the second heating element are located closer to each other can reach a higher temperature than a portion in which the first heating element and the second heating element are located further apart.

The second heating element may comprise a first portion. The second heating element may comprise a second portion. The second heating element may comprise a third portion. The second heating element may comprise a fourth portion. The second heating element may comprise a fifth portion.

The second section may extend between the first section and the third section. The third section may extend between the second section and the fourth section.

The first portion of the second heating element may be integrated into the component for storing the liquid aerosol-forming substrate. The second portion of the second heating element may not be integrated into the component for storing the liquid aerosol-forming substrate. The third portion of the second heating element may be integrated into the component for storing the liquid aerosol-forming substrate. The fourth portion of the second heating element may not be integrated into the component for storing the liquid aerosol-forming substrate. The fifth portion of the second heating element may be located in the reservoir.

This can advantageously create more regions with relatively higher temperature and more regions with relatively lower temperature in the aerosol-forming liquid substrate storage component.

The second heating element may enter and exit the aerosol-forming liquid substrate storage component.

The second heating element may comprise one or more of curved portions, wavy portions, folds, and corrugations.

The second heating element may be located at a distance from the heating element in a direction transverse to the length of the heating element. The second heating element may be located at a distance from the heating element in the direction of the width of the heating element. The second heating element may be located adjacent to the first heating element.

The second heating element may be a mesh heating element. The second heating element may comprise a mesh.

The first heating element and the second heating element may not be electrically connected.

The first heating element may be configured to provide induction heating.

The first and second heating elements may operate independently of each other. It may be possible to resistively or inductively heat the first heating element without significantly heating the second heating element. It may be possible to increase the temperature of the first heating element without significantly increasing the temperature of the second heating element. The first and second heating elements may be connected to different power sources.

The first part or the second part, or both the first part and the second part of the heating element can be configured to heat up to at least 50, 100, 150, 200, 250, 300, 350, or 400 degrees Celsius. In use, the first part or the second part, or both the first part and the second part of the heating element can be heated up to at least 50, 100, 150, 200, 250, 300, 350, or 400 degrees Celsius.

The third part, or the fourth part, or both the third part and the fourth part of the heating element can be configured to heat up to at least 50, 100, 150, 200, 250, 300, 350, or 400 degrees Celsius. In use, the third part, or the fourth part, or both the third part and the fourth part of the heating element can be heated up to at least 50, 100, 150, 200, 250, 300, 350, or 400 degrees Celsius.

The fifth portion of the heating element may be configured to heat up and may, in use, heat up to at least 50, 100, 150, 200, 250, 300, 350, or 400 degrees Celsius. In use, the fifth portion of the heating element may heat up to at least 50, 100, 150, 200, 250, 300, 350, or 400 degrees Celsius.

The component for storing the liquid aerosol-forming substrate may be configured to store or may store at least 0.02, 0.05, 0.1, 0.2 or 0.5 milliliters of the liquid aerosol-forming substrate.

According to another aspect of the present invention

A method for assembling a heater assembly is provided. The heater assembly may be a heater assembly according to the present invention. The method may include providing a component for storing a liquid aerosol-forming substrate. The method may include providing a heating element comprising a first part and a second part. The method may include integrating the first part of the heating element into the component for storing the liquid aerosol-forming substrate.

If the heating element comprises a third portion, the method may include embedding the third portion of the heating element in a component for storing a liquid aerosol-forming substrate.

According to another aspect of the present invention, a cartridge is provided. The cartridge may comprise a heater assembly according to the present invention.

The cartridge may be configured to be engaged and disengaged from the aerosol-generating device. The aerosol-generating device may comprise a power source. The power source may be configured to supply power to a heating element. The power source may be configured to supply power to the heating element only when the cartridge is engaged with the aerosol-generating device.

The cartridge may include an air inlet. The cartridge may include an air outlet. The air inlet may be in fluid communication with the air outlet. A heating element may be located downstream of the air inlet. The heating element may be located upstream of the air outlet. In use, this may allow air to flow through the air inlet, then through, over, past, or through the heater assembly or heating element, then through the air outlet.

The cartridge may contain a mouthpiece. The mouthpiece may contain an air outlet. During use, when the cartridge is attached to an aerosol-generating device, the user draws on the cartridge's mouthpiece. This may cause air to flow through the air inlet, then through, over, past, or through the heater assembly or heating element, then through the air outlet.

Advantageously, providing an air flow through, over, past, or through the heater assembly or heating element may ensure that steam generated by the heater assembly is entrained in the air flow.

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

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

The second portion, or the fourth portion, or both the second portion and the fourth portion of the heating element may be located in the air flow path between the air inlet of the cartridge and the air outlet of the cartridge.

This can increase the airflow temperature, which may be preferable for some users. It can more closely mimic the experience of smoking a regular cigarette or cigar.

According to another aspect of the present invention, an aerosol generating system is provided. The system may comprise a heater assembly according to the present invention.

The aerosol generating system may comprise a cartridge according to the present invention.

The system may include an aerosol-generating device. The system may include a cartridge containing a heater assembly.

The cartridge may be configured to be engaged with the aerosol-generating device. The cartridge may be configured to be disengaged from the aerosol-generating device.

An aerosol-generating system, such as an aerosol-generating device, of an aerosol-generating system may include a power supply, such as a battery. The power supply may be configured to supply power to a heating element. This may be used to heat the heating element. The power supply may be configured to supply power to the heating element only when the cartridge is engaged with the aerosol-generating device.

The aerosol-generating device may include a controller. The controller may be configured to control the power supply from a power supply unit. Thus, the controller can control the heating of the heating element.

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.

The aerosol-generating device may be configured to engage and disengage the cartridge via a snap-fit connection, corresponding screw threads, or any other suitable means. The aerosol-generating device may be configured to accommodate at least a portion of the cartridge. For example, the aerosol-generating device may comprise a chamber configured to accommodate at least a portion of the cartridge.

The aerosol-generating device may include an air inlet. The aerosol-generating device may include 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.

The power supply may be electrically connected to 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 supply may be configured to supply power to the heating element by allowing electric current to flow through the heating element.

The cartridge or aerosol generating device may contain an inductor, such as an induction coil.

The heating element may be or may comprise a current-collecting material.

A power supply can be configured to allow a current, such as high-frequency alternating current, to flow through an inductor, causing the inductor to generate an oscillating electromagnetic field. This, in turn, can lead to eddy currents and hysteresis losses in the current-collecting material. This can cause heating of the current-collecting material. Thus, a power supply using an inductor can be configured to inductively heat the heating element.

Suitable current-collecting materials include those previously mentioned with respect to the heater assembly of the present invention.

The inductor may be an induction coil. The inductor may be located in the cartridge containing the heater assembly. The inductor may be positioned around the heating element or a portion of the heating element. For example, the inductor may be an induction coil and may spiral around the heating element or a portion of the heating element.

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, which are electrically connected to a power supply within the device. When the cartridge is engaged with the device, the device's power supply may be configured to allow current to flow through the inductor to create a fluctuating electromagnetic field, thereby heating the current-receiving material of the heating element.

An inductor, such as an induction coil, may be located in the aerosol-generating device. The inductor may be electrically connected to a power supply unit of the aerosol-generating device. The aerosol-generating device may be configured to engage with a heater assembly or a cartridge containing the heater assembly. For example, the device may comprise a chamber for containing at least a portion of the heater assembly or at least a portion of the cartridge containing the heater assembly. The induction coil may be located around at least a portion of this chamber. For example, the induction coil may extend in a spiral around at least a portion of the chamber. Thus, when the heater assembly or the cartridge containing the heater assembly is engaged with the device, the induction coil may be located around or extend in a spiral around the heating element or a portion of the heating element. When at least a portion of the heater assembly or at least a portion of the cartridge containing the heater assembly is housed within the chamber of the device, the power supply unit of the device may be configured to provide current flow through the inductor to create an oscillating electromagnetic field and thereby heat the current-receiving material of the heating element.

As mentioned above, induction heating can advantageously produce a cartridge that is simple, inexpensive, and reliable. Furthermore, induction heating can provide improved energy conversion compared to resistive heating.

The aerosol-generating system may be a smoking system, such as an electric smoking system. The aerosol-generating system may be intended for recreational use. In use, the aerosol-generating system may be suitable for delivering nicotine to the user, or configured to deliver it.

The aerosol-generating system may be portable. The aerosol-generating system may be comparable in size to a traditional cigar or cigarette. The smoking system may have an overall length of between 30 millimeters and 200 millimeters. The smoking system may have an outer diameter of between 5 millimeters and 30 millimeters. As used herein, the term "aerosol" refers to a dispersion of solid particles, liquid droplets, or a combination of solid particles and liquid droplets in a gas. An aerosol may be visible or invisible. An aerosol may contain vapors of substances that are normally liquid or solid at room temperature, as well as solid particles, liquid droplets, or a combination of solid particles and liquid droplets.

For the purposes of this document, the term "aerosol-forming substrate" refers to a substrate capable of releasing volatile compounds that can form an aerosol. The volatile compounds can be released by heating or burning the aerosol-forming substrate.

An aerosol-forming substrate may contain multiple compounds. The compounds may have different boiling points. For example, an aerosol-forming substrate may contain a first compound with a first boiling point at atmospheric pressure and a second compound with a second boiling point at atmospheric pressure, where the first boiling point is higher than the second boiling point.

The aerosol-forming substrate may comprise an aerosol former. As used herein, the term "aerosol former" refers to any suitable compound or mixture of compounds that, when used, facilitates the formation of an aerosol, such as a stable aerosol, i.e., one that is substantially resistant to thermal degradation 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, and glycerol; esters of polyhydric alcohols such as glycerol mono-, di-, or triacetate; and aliphatic esters of mono-, di-, or polycarboxylic acids such as dimethyl dodecanedioate and dimethyl tetradecanedioate.

The aerosol-forming substrate may contain nicotine. The aerosol-forming substrate may contain water. The aerosol-forming substrate may contain glycerol, also known as glycerin, which has a higher boiling point than nicotine. The aerosol-forming substrate may contain propylene glycol. The aerosol-forming substrate may contain plant-based material. The aerosol-forming substrate may contain homogenized plant-based material. The aerosol-forming substrate may contain tobacco. The aerosol-forming substrate may contain tobacco-containing material. The tobacco-containing material may contain volatile aromatic compounds of tobacco. These compounds can be released from the aerosol-forming substrate upon heating. The aerosol-forming substrate may contain homogenized tobacco material. The aerosol-forming substrate may contain other additives and ingredients such as fragrances.

For the purposes of this document, the term "liquid aerosol-forming substrate" refers to the aerosol-forming substrate in condensed form. Thus, the "liquid aerosol-forming substrate" may be or comprise one or more of a liquid, a gel, or a paste. If the liquid aerosol-forming substrate is or comprises a gel or paste, the gel or paste may liquefy upon heating. For example, the gel or paste may liquefy upon heating to a temperature below 50, 75, 100, 150, or 200 degrees Celsius.

As used in this document, the term "heating element" refers to a heating element, wherein the element is capable of heating. For example, the term

"Heating element" may refer to an element capable of heating to at least 50, 100, 150, 200, 250, 300, 350, or 400 degrees Celsius. The heating element or portions thereof may be capable of resistive heating. Alternatively or additionally, the heating element or portions thereof may be capable of induction heating.

In the context of this document, the term "embedded" may be used to mean "surrounded," "encased," "enclosed," "enclosed," or "enclosed." Furthermore, when a first component is "embedded" within a second component, this may mean that the first component is in contact with the second component. For example, when a portion of a heating element is described as embedded within a component, this may mean that this portion of the heating element is enclosed by the component and in contact with it.

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

Example Ex1. A heater assembly for use in an aerosol generating system, the heater assembly comprising:

a component for storing a liquid aerosol-forming substrate; and

a heating element comprising a first part and a second part,

wherein the first part of the heating element is built into the component for storing the liquid substrate that forms the aerosol, and the second part of the heating element is not built into the component for storing the liquid substrate that forms the aerosol.

Example Ex2. A heater assembly according to example Ex1, in which the heating element comprises a third part and a fourth part, wherein the third part of the heating element is built into a component for storing a liquid aerosol-forming substrate, and the fourth part is not built into a component for storing a liquid aerosol-forming substrate.

Example Ex3. A heater assembly according to example Ex2, wherein the second portion of the heating element extends between the first portion and the third portion.

Example Ex4. A heater assembly according to example Ex2 or example Ex3, in which the third portion of the heating element extends between the second portion and the fourth portion.

Example Ex5. A heater assembly according to any of the examples Ex2-Ex4, wherein the third part and the fourth part are designed to be resistively heated.

Example Ex6. A heater assembly according to any of the examples Ex2-Ex5, wherein the third part and the fourth part comprise an electrically resistive material.

Example Ex7. A heater assembly according to any of the previous examples, wherein the first part and the second part are designed to be resistively heated.

Example Ex8. A heater assembly according to any of the previous examples, wherein the first part and the second part comprise an electrically resistive material.

Example Ex9. A heater assembly according to any of the examples Ex2-Ex4, wherein the third part and the fourth part are designed with the possibility of induction heating.

Example Ex10. A heater assembly according to any of the examples Ex2-Ex4 or Ex9, wherein the third part and the fourth part comprise a current-collecting material.

Example Ex11. A heater assembly according to any of the examples Ex1-Ex4, Ex9 or Ex10, wherein the first part and the second part are designed with the possibility of induction heating.

Example Ex12. A heater assembly according to any of the examples Ex1-Ex4, Ex9, Ex10 or Ex11, wherein the first part and the second part comprise a current-collecting material.

Example Ex13. A heater assembly according to any of the previous examples, wherein the heating element comprises a strip of material.

Example Ex14. A heater assembly according to any of the previous examples, wherein the cross-section

heating element varies along the length of the heating element.

Example Ex15. A heater assembly according to any of the previous examples, wherein the minimum cross-sectional area along the length of the heating element is at least 10 percent less than the maximum cross-sectional area along the length of the heating element.

Example Ex16. A heater assembly according to any of the previous examples, wherein the width or thickness, or both the width and thickness of the heating element vary along the length of the heating element.

Example Ex17. A heater assembly according to any of the previous examples, wherein the heating element enters and exits the component for storing the liquid substrate that forms the aerosol.

Example Ex18. A heater assembly according to any of the previous examples, wherein the heating element comprises one or more of curved portions, wavy portions, folds and corrugations.

Example Ex19. A heater assembly according to any of the previous examples, wherein the heating element comprises one or more irregular wavy portions and irregular corrugations along the length of the heating element.

Example Ex20. A heater assembly according to any of the previous examples, in which the frequency of the wavy portions or corrugations of the heating element varies along the length of the heating element.

Example Ex21. A heater assembly according to any of the previous examples, wherein the amplitude of the wavy portions or corrugations of the heating element varies along the length of the heating element.

Example Ex22. A heater assembly according to any of the previous examples, comprising a reservoir for storing a liquid aerosol-forming substrate.

Example Ex23. A heater assembly according to Ex22, in which the reservoir is in fluid communication with the component for storing the liquid aerosol-forming substrate.

Example Ex24. A heater assembly according to Ex22 or Ex23, in which the heating element comprises a fifth part, wherein the fifth part is located in the reservoir.

Example Ex25. A heater assembly according to Ex22, Ex23 or Ex24, wherein the reservoir contains at least 1 millilitre of a liquid aerosol-forming substrate.

Example Ex26. A heater assembly according to any of the previous examples, comprising a second heating element.

Example Ex27. A heater assembly according to Ex26, wherein the second heating element enters and exits the component for storing the liquid aerosol-forming substrate.

Example Ex28. A heater assembly according to Ex26 or Ex27, wherein the second heating element comprises one or more of curved portions, wavy portions, folds and corrugations.

Example Ex29. A heater assembly according to any of the examples Ex26-Ex28, wherein the second heating element is located at a distance from the heating element in a direction transverse to the length of the heating element.

Example Ex30. A heater assembly according to any of examples Ex26-Ex29, wherein the second heating element is a mesh heating element.

Example Ex31. A heater assembly according to any of the previous examples, wherein in use both the first part and the second part are heated to at least 50 degrees Celsius.

Example Ex32. A heater assembly according to any of the previous examples, wherein the heating element is a mesh heating element.

Example Ex33. A heater assembly according to any of the previous examples, wherein the component for storing the liquid aerosol-forming substrate comprises a capillary-retaining material.

Example Ex34. A heater assembly according to any of the previous examples, wherein the component for storing the liquid aerosol-forming substrate is configured to store at least 0.05 milliliters of the liquid aerosol-forming substrate.

Example Ex35. A heater assembly according to any of the previous examples, wherein at least 0.05 milliliters of a liquid aerosol-forming substrate is stored in a component for storing a liquid aerosol-forming substrate.

Example Ex36. A cartridge containing a heater assembly according to any of the previous examples.

Example Ex37. A method for assembling a heater assembly according to any of the examples Ex1-Ex35, wherein the method comprises:

providing a component for storing a liquid aerosol-forming substrate;

providing a heating element comprising a first portion and a second portion; and

embedding the first part of the heating element into a component for storing a liquid substrate that forms an aerosol.

Example Ex38. An aerosol generating system comprising a heater assembly according to any of the examples Ex1 to Ex35.

Example Ex39. An aerosol generating system according to Ex38, wherein the system comprises an aerosol generating device and a cartridge containing a heater assembly.

Example Ex40. An aerosol generating system according to Ex39, in which the cartridge is configured to be engaged and disengaged from the aerosol generating device.

Example Ex41. An aerosol generating system according to any of examples Ex38, Ex39 and Ex40, wherein the aerosol generating system comprises a power supply unit configured to supply power to a heating element for heating the heating element.

Example Ex42. An aerosol generating system according to Ex39 or Ex40, wherein the aerosol generating device comprises a power supply unit configured to supply power to a heating element for heating the heating element.

Example Ex43. An aerosol generating system according to Ex41 or Ex42, wherein the power supply unit is configured to supply power to the heating element for resistively heating the heating element.

Example Ex44. An aerosol generating system according to Ex41 or Ex42, in which the power supply unit is configured to supply power to the heating element for inductively heating the heating element.

Example Ex45. An aerosol generating system according to any of examples Ex38 to Ex44, wherein the aerosol generating system has an overall length of between 30 millimetres and 200 millimetres.

Example Ex46. An aerosol generating system according to any of examples Ex38 to Ex45, wherein the aerosol generating system has an outer diameter of from 5 millimetres to 30 millimetres.

Example Ex47. An aerosol generating system according to any of examples Ex38 to Ex46, wherein the aerosol generating system is portable.

Example Ex48. An aerosol generating system according to any of examples Ex38 to Ex47, wherein the aerosol generating system is a smoking system.

The examples will now be further described with reference to figures, where:

Fig. 1 shows a schematic cross-sectional view of a first aerosol generating system comprising a cartridge comprising a first heater assembly;

Fig. 2 shows a schematic cross-sectional view of the first heater assembly;

Fig. 3 shows a schematic perspective view of the first heater assembly;

Fig. 4 is a schematic cross-sectional view of a second aerosol generating system comprising a cartridge comprising a second heater assembly;

Fig. 5 shows a schematic cross-sectional view of the second heater assembly; and

Fig. 6 shows a schematic perspective view of the second heater assembly.

Fig. 1 shows a schematic cross-sectional view of a first aerosol generating system 100. The aerosol generating system 100 comprises an aerosol generating device 150 and a cartridge 200. In this example, the aerosol generating system 100 is an electric smoking system.

The aerosol generating device 150 is portable and has a size comparable to that of a traditional cigar or cigarette. The device 150 comprises a battery 152, such as a lithium iron phosphate battery, and a controller 154 electrically connected to the battery 152. The device 150 also comprises two electrical contacts 156, 158, which are electrically connected to the battery 152. This electrical connection is a wired connection and is not shown in Fig. 1.

The cartridge 200 comprises first and second electrical contacts 214, 216, an air inlet 202, an air outlet 204 and a first heater assembly 300. The air inlet 202 is in fluid communication with the air outlet 204. The heater assembly 300 is located downstream of the air inlet 202 and upstream of the air outlet 204. The heater assembly 300 comprises a component 302 for storing a liquid aerosol-forming substrate in fluid communication with a reservoir 303 with a liquid aerosol-forming substrate. The heater assembly 300 also comprises a heating element 304. The first and second electrical contacts 214, 216 are electrically connected to the heating element 304.

In this system, 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 can 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 initially heating this liquid aerosol-forming substrate to form the aerosol, some systems may undesirably vaporize a disproportionately large amount of propylene glycol (which has the lowest boiling point among the substrate-forming compounds). This may result in the delivery of a less desirable aerosol to the user, since the aerosol contains a lower proportion of nicotine than desired. This may also undesirably change the relative proportions of the compounds in the substrate over a longer period of time. The present invention can eliminate or at least reduce these undesirable effects.

The heating element 304 is a strip of material. In this example, the material is stainless steel, although any suitable material can be used. The heating element 304 comprises a first portion 306, a second portion 308, a third portion 310, and a fourth portion 312. The second portion 308 extends between the first portion 306 and the third portion 310. The third portion 310 extends between the second portion 308 and the fourth portion 312. The first portion 306 and the third portion 310 are integrated into the component 302 for storing the liquid aerosol-forming substrate. The second portion 308 and the fourth portion 312 are not integrated into the component 302 for storing the liquid aerosol-forming substrate. In the example shown in Fig. 1, the second portion 308 and the fourth portion 312 are located in the air flow path between the air inlet 202 and the air outlet 204 of the cartridge 200.

In Fig. 1, the aerosol generating device 150 is engaged with the cartridge 200. In this example, the cartridge 200 is engaged with the aerosol generating device 150 by mating the screw thread 206 of the cartridge 200 with the corresponding screw thread 162 of the aerosol generating device 150.

In this example, component 302 for storing the liquid aerosol-forming substrate is a capillary material having a fibrous structure. In the example shown in Fig. 1, the capillary material is formed from polyester, although any suitable material can be used.

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 this button sends a signal to the controller 154, resulting in power being supplied from the battery 152 to the heating element 304 via the electrical contacts 156, 158 of the device and the electrical contacts 214, 216 of the cartridge. This causes current to flow through the heating element 304, causing the heating element 304 to resistively heat. In other examples, an air flow sensor or pressure sensor is located in the cartridge 200 and is electrically connected to the controller 154. The air flow sensor or pressure sensor detects that the user is taking a puff 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 examples, the user does not need to press a button to heat the heating element 304.

As the heating element 304 heats up, regions of relatively higher temperature and regions of relatively lower temperature are created in the component 302 for storing the liquid aerosol-forming substrate. Regions of relatively lower temperature may be created in regions where the heating element 304 is located closer to the reservoir 303 containing the liquid aerosol-forming substrate. This occurs because the heat from the heating element 304 in these regions is more quickly dissipated into the reservoir 303. Regions of relatively lower temperature may be created in regions located further from the heating element. Due to the shape of the heating element, regions of relatively higher temperature may be created. For example, the heating element may have a shape such that a given volume in a first location in the component for storing the liquid aerosol-forming substrate contains a greater volume or a greater surface area of the heating element than the same given volume in a second location in the component for storing the liquid aerosol-forming substrate. In this case, the average temperature of the aerosol-forming liquid substrate in the first location may be greater than the average temperature of the aerosol-forming liquid substrate in the second location.

The creation of higher-temperature and lower-temperature regions results in the simultaneous evaporation of the higher-boiling and lower-boiling liquid aerosol-forming substrate compounds in the aerosol-forming liquid substrate storage component 302. The creation of higher-temperature and lower-temperature regions also results in the evaporation of the higher-boiling and lower-boiling liquid aerosol-forming substrate compounds in the aerosol-forming liquid substrate storage component 302 at the desired rates.

When the user draws on air outlet 204 of cartridge 200, air is drawn into air inlet 202. This air then passes through heater assembly 300 and to air outlet 204. This air flow entrains vapor generated by heating element 304, heating the aerosol-forming liquid substrate in aerosol storage component 302. By creating higher-temperature and lower-temperature regions, as explained above, the vapor contains the desired proportions of different compounds with different boiling points. This entrained vapor then cools and condenses to form an aerosol. This aerosol is then delivered to the user through air outlet 204. As the liquid aerosol-forming substrate in the liquid aerosol-forming substrate storage component 302 is heated, evaporated, and entrained by the air flow, the liquid aerosol-forming substrate passes from the reservoir 303 into the liquid aerosol-forming substrate storage component 302. This liquid aerosol-forming substrate from the reservoir 303 effectively replaces the evaporated liquid aerosol-forming substrate. The liquid aerosol-forming substrate from the reservoir 303 can be drawn into the liquid aerosol-forming substrate storage component 302 at least partially by capillary action. This is due to the fact that the liquid aerosol-forming substrate storage component 302 is a capillary material having a fibrous structure.

Fig. 2 shows a schematic sectional view of the first heater assembly 300. The width of the heating element 304, which in Fig. 2 is located in the direction inside the page, can vary, but in the example shown in Fig. 2, it is constant. However, as shown in Fig. 2, the thickness of the heating element 304 is not constant. Rather, the thickness gradually decreases from the second part 308 to the third part 310, and then gradually increases from the third part 310 to the fourth part 312. The minimum thickness of the heating element 304 is in the third part 310, which is built into the component 302 for storing the liquid substrate that forms the aerosol. This minimum thickness of heating element 304 is approximately 50 percent of the maximum thickness of the heating element in first portion 306. Therefore, the resistance of third portion 310 is greater than the resistance of the other portions, and during use, third portion 310 will resistively heat to a higher temperature than the other portions. This can advantageously increase the temperature of the liquid substrate forming the aerosol near third portion 310 of heating element 304.

Fig. 3 shows a schematic perspective view of the first heater assembly 300. As shown in Fig. 3, the heating element 304 has curved portions and enters and exits the component 302 for storing the liquid aerosol-forming substrate. The ends of the heating element 304 extend outward from the component 302 for storing the liquid aerosol-forming substrate, providing an easy electrical connection with the electrical contacts (not shown in Fig. 3) of the cartridge 200.

Fig. 4 shows a schematic cross-sectional view of a second aerosol generating system 400. The aerosol generating system 400 comprises an aerosol generating device 450 and a cartridge 500 comprising a second heater assembly 600. In this example, the aerosol generating system 400 is an electric smoking system.

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

The cartridge 500 comprises an air inlet 502, an air outlet 504, and a second heater assembly 600. The air inlet 502 is in fluid communication with the air outlet 504. The heater assembly 600 is located downstream of the air inlet 502 and upstream of the air outlet 504. When the cartridge 500 is engaged with the aerosol generating device 450, as shown in Fig. 4, the air outlet 460 of the device 450 is adjacent to the air inlet 502 of the cartridge 500. Thus, in use, when the user takes a puff on the air outlet 504 of the cartridge 500, the 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 past the heater assembly 600, then through the air outlet 504 of the cartridge 500.

In Fig. 4, cartridge 500 is engaged with aerosol generating device 450. In this example, cartridge 500 is engaged with aerosol generating device 450 via openings 506, 508 that form a snap connection with corresponding projections 462, 464 on aerosol generating device 450.

The heater assembly 600 comprises a first heating element 604, a second heating element (not visible in Fig. 4), a reservoir 603 with a liquid aerosol-forming substrate, and a component 602 for storing the liquid aerosol-forming substrate in fluid communication with the reservoir 603. The second heating element 605 is not visible in Fig. 4, but is visible in Fig. 6.

In this system 400, the liquid aerosol-forming substrate comprises approximately 98% by weight glycerin and 2% by weight nicotine, although any suitable substrate can be used. At atmospheric pressure, nicotine has a boiling point of approximately 247 degrees Celsius, and glycerin has a boiling point of approximately 290 degrees Celsius. Therefore, when initially heating this liquid aerosol-forming substrate to form the aerosol, some systems may undesirably vaporize a disproportionately large amount of nicotine (which has the lowest boiling point among the compounds forming the substrate). This may result in the delivery of a less desirable aerosol to the user. It may also undesirably change the relative proportions of the compounds in the substrate over a longer period of time. The present invention can eliminate or at least reduce these undesirable effects.

The first heating element 604 comprises a strip of susceptor material. In this example, the susceptor material is aluminum, although any suitable susceptor material can be used. The first heating element 604 comprises several parts integrated into the component 602 for storing the liquid aerosol-forming substrate, and several parts not integrated into the component 602 for storing the liquid aerosol-forming substrate. Of the parts not integrated into the component 602 for storing the liquid aerosol-forming substrate, two are located in the reservoir 603.

In the example shown in Fig. 4, the second heating element 605 is identical to the first heating element 604, although two (or more) different heating elements may be used. The second heating element 605 is located adjacent to the first heating element 604.

In this example, component 602 for storing the liquid aerosol-forming substrate is a capillary material with a fibrous structure. The capillary material is formed from polyester, although any suitable material can be used.

In use, the 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 this button sends a signal to the controller 454, causing the battery 452 to supply a high-frequency electric current to the induction coil 456. This causes the induction coil 456 to generate an oscillating electromagnetic field. The first heating element 604 and the second heating element 605 are located within this field. Thus, this oscillating electromagnetic field generates eddy currents and hysteresis losses in the first heating element 604 and the second heating element 605. Thus, the first heating element 604 and the second heating element 605 are inductively heated. In other examples, an air flow sensor or a pressure sensor is located in the device 450 and is electrically connected to the controller 454. The air flow sensor or the pressure sensor detects that the user is taking a puff on the air outlet 504 of the cartridge 500 and sends a signal to the controller 454 to supply a high-frequency electric current to the induction coil 456, thereby heating the first heating element 604 and the second heating element 605. Thus, in these examples, the user does not need to press a button to heat the first heating element 604 and the second heating element 605.

As the first heating element 604 and the second heating element 605 heat up, regions of relatively higher temperature and regions of relatively lower temperature are created in the component 602 for storing the liquid aerosol-forming substrate. Regions of lower temperature may be created in regions where the heating element 604 is located closer to the reservoir 603 with the liquid aerosol-forming substrate. This occurs because the heat from the heating element 604 in these regions is more quickly dissipated into the reservoir 603. Regions of relatively lower temperature may be created in regions located further from the heating element. Due to the shape of the heating element, regions of relatively higher temperature may be created. For example, the heating element may have a shape such that in a given volume in the first location in the component for storing the liquid aerosol-forming substrate, there is a greater volume or a greater surface area of the heating element than in the same given volume in the second location in the component for storing the liquid aerosol-forming substrate. In this case, the average temperature of the aerosol-forming liquid substrate in the first location may be greater than the average temperature of the aerosol-forming liquid substrate in the second location.

The creation of higher-temperature and lower-temperature regions results in the simultaneous evaporation of the higher-boiling and lower-boiling liquid aerosol-forming substrate compounds in the aerosol-forming liquid substrate storage component 602. The creation of higher-temperature and lower-temperature regions also results in the evaporation of the higher-boiling and lower-boiling liquid aerosol-forming substrate compounds in the aerosol-forming liquid substrate storage component 302 at the desired rates.

When the user takes a puff 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, then through the air inlet 502 of the cartridge 500. This air then passes around the heater assembly 600 and to the air outlet 504. This air flow entrains the vapor formed by heating the liquid substrate that forms the aerosol by the first heating element 604 and the second heating element 605. By creating regions of higher temperature and regions of lower temperature, as explained above, the vapor contains the desired proportions of different compounds with different boiling points. This entrained vapor is then cooled and condensed to form an aerosol. This aerosol is then delivered to the user through the air outlet 504.

Fig. 5 shows a schematic cross-sectional view of the second heater assembly 600.

The first heating element 604 comprises a first part 606, a second part 608, a third part 610, a fourth part 612, a fifth part 614, a sixth part 616, a seventh part 618, an eighth part 620 and a ninth part 622. The first part 606, the third part 610, the fifth part 614, the seventh part 618 and the ninth part 622 are built into the component 602 for storing the liquid substrate that forms the aerosol. The second part 608, the fourth part 612, the sixth part 616 and the eighth part 620 are not built into the component 602 for storing the liquid substrate that forms the aerosol. The second part 608 and the eighth part 620 are located in the air flow path between the air inlet 502 and the air outlet 504 of the cartridge 500. The fourth part 612 and the sixth part 616 are located in the reservoir 603 of the liquid substrate that forms the aerosol.

In Fig. 5, the varying thickness of the first heating element 604 can be seen. The central section of the fifth part 614 has a reduced thickness compared to the rest of the first heating element 604. In particular, the thickness in the central section of the fifth part 616 is approximately 30 percent of the thickness of the rest of the first heating element 604. As shown in Fig. 5, the fifth part 614 also contains corrugations. The portion of the component 602 for storing the liquid aerosol-forming substrate around the fifth part 614 can be heated to a relatively higher temperature than other portions of the component 602 for storing the liquid aerosol-forming substrate. This is due to the fact that the fifth part 614 of the heating element 604 is thinner, which can lead to the induction heating of the fifth part 614 to a higher temperature than other parts of the heating element 604. Alternatively or additionally, the corrugations in the fifth part 614 mean that the region of the component 602 for storing the liquid aerosol-forming substrate around the fifth part 614 contains a larger volume and a larger surface area of the heating element 604 than other regions of the component 602 for storing the liquid aerosol-forming substrate of a similar size. Thus, more heat can be transferred from the heating element 604 to the region of the component 602 for storing the liquid aerosol-forming substrate around the fifth part 614 than to other regions.

In Fig. 6 a schematic perspective view of the second heater assembly 600 is shown. In Fig. 6 a second heating element 605 is visible. The second heating element 605 is identical to the first heating element 604 and is located adjacent to the first heating element 604. Therefore, the second heating element 605 similarly has parts integrated into the component 602 for storing the liquid substrate that forms the aerosol, parts located in the reservoir 603, and parts located in the air flow path between the air inlet 502 and the air outlet 504 of the cartridge 500. In Fig. 6 a second part 608 and an eighth part 620 of the first heating element 604 are also visible.

The heater assemblies described herein may provide higher-temperature regions and lower-temperature regions within the aerosol-forming liquid substrate storage component. Alternatively, or additionally, the heater assemblies may provide regions in which the temperature increases at a faster rate and regions in which the temperature increases at a slower rate within the aerosol-forming liquid substrate storage component.

Advantageously, as explained above, this can result in the simultaneous evaporation at desired rates of the higher boiling point and lower boiling point compounds of the liquid aerosol-forming substrate.

For the purposes of the present description and the appended claims, except where otherwise indicated, all numbers expressing quantities, amounts, percentages, etc., are to be understood as modified in all instances by the term "about." Also, all ranges include the disclosed maximum and minimum points and include any intermediate ranges therebetween, which may or may not be specifically listed herein. Therefore, in this context, the number A is to be understood as A±10 percent of A. In this context, the number A may be considered to include numerical values that are within the normal standard error for the measurement of the property that the number A modifies. The number A, in some instances, when used in the appended claims, may deviate by the percentages listed above, provided that the amount by which A deviates does not materially affect the essential and novel characteristic(s) of the claimed invention. All ranges also include the disclosed high and low points and include any intermediate ranges therebetween that may or may not be specifically listed herein.

Claims (17)

1. A heater assembly for use in an aerosol generating system, the heater assembly comprising: a component for storing a liquid aerosol-forming substrate; and a reservoir for a free-flowing liquid aerosol-forming substrate, wherein the reservoir is in fluid communication with the component for storing the liquid aerosol-forming substrate; a heating element comprising a first part, a second part and an additional part, wherein the first part of the heating element is built into the component for storing the liquid substrate that forms the aerosol, the second part of the heating element is not built into the component for storing the liquid substrate that forms the aerosol, and the additional part of the heating element is located in the reservoir. 2. The heater assembly according to paragraph 1, characterized in that the heating element comprises a third part and a fourth part, wherein the third part of the heating element is built into the component for storing the liquid substrate that forms the aerosol, and the fourth part is not built into the component for storing the liquid substrate that forms the aerosol, wherein the second portion of the heating element extends between the first portion and the third portion, and the third portion of the heating element extends between the second portion and the fourth portion. 3. A heater assembly according to any of the preceding paragraphs, characterized in that the heating element comprises a strip of material having a length, a width perpendicular to the length, and a thickness perpendicular to the length and width, wherein the length is greater than the width and greater than the thickness. 4. A heater assembly according to any of the preceding paragraphs, characterized in that the cross-section of the heating element varies along the length of the heating element. 5. A heater assembly according to any one of the preceding claims, characterized in that the heating element extends between the first end and the second end, and the heating element has a first cross-sectional area at a first point between the first end and the second end, a second cross-sectional area at a second point between the first point and the second end, and a third cross-sectional area at a third point between the second point and the second end, and each of the first cross-sectional area and the third cross-sectional area is greater than or less than the second cross-sectional area. 6. A heater assembly according to any of the preceding paragraphs, characterized in that the heating element enters into and exits from the component for storing the liquid substrate that forms the aerosol. 7. A heater assembly according to any of the preceding paragraphs, characterized in that the heating element comprises one or more of: curved portions, wavy portions, folds and corrugations. 8. A heater assembly according to any of the preceding paragraphs, characterized in that it contains a second heating element. 9. The heater assembly according to claim 8, characterized in that the second heating element comprises a first section and a second section, wherein the first section of the second heating element is built into the component for storing the liquid substrate that forms the aerosol, and the second section of the second heating element is not built into the component for storing the liquid substrate that forms the aerosol. 10. A heater assembly according to any of the preceding claims, characterized in that, in use, both the first part and the second part are heated to at least 50 degrees Celsius. 11. An aerosol generating system comprising a heater assembly according to any of the preceding claims. 12. The aerosol generating system of claim 11, wherein the system comprises an aerosol generating device and a cartridge containing a heater assembly, wherein the cartridge is configured to be engaged and disengaged from the aerosol generating device.