Heater assembly with porous body

Abstract

An aerosol-generating system (200) comprises a heater assembly (100) comprising a heating element for vaporizing a liquid aerosol-forming substrate, and a porous body for delivering the liquid aerosol-forming substrate to the heating element. The porous body has a liquid absorbing surface (111) and a heating surface (112). The heating element is located on a heating surface (112) of the porous body. The heating element and the porous body are integrally formed. The average pore size of the porous body varies between the liquid absorbing surface (111) and the heating surface (112). The aerosol-generating system (200) also includes an air inlet (302) and an aerosol outlet (305), the air inlet (302) being in fluid communication with the aerosol outlet (305) to define an airflow path through the aerosol-generating system (200). The heater assembly (100) is arranged in fluid communication with the airflow path such that air flows through the heater assembly (100) in an average airflow direction, where the heater assembly (100) and the airflow path are arranged such that an angle between an average vapor discharge direction and the average airflow direction is less than 135 degrees.

Description

Technical Field

[0001] This invention relates to a heater assembly for use in an aerosol generation system. More specifically, the invention relates to a heater assembly for use in an aerosol generation system, the heater assembly comprising a heating element and a porous body. Background Technology

[0002] Aerosol generation systems that heat a liquid aerosol forming matrix to generate an aerosol for delivery to a user are generally known in the art. These systems typically include an aerosol generating device and a replaceable cartridge. The cartridge contains a liquid aerosol forming matrix capable of releasing volatile compounds when heated. The cartridge typically includes a heater for heating the liquid aerosol forming matrix. In known aerosol generation systems, the heater includes a resistance heating element wound around a core that supplies the liquid aerosol forming matrix to the heating element. The aerosol generating device or cartridge also includes a mouthpiece. When a user inhales through the mouthpiece, an electric current passes through the heating element, heating it by resistance or Joule heating, which in turn heats the liquid aerosol forming matrix supplied by the core. This causes the release of volatile compounds from the liquid aerosol forming matrix, which cool to form an aerosol. The aerosol is then inhaled into the user's mouth via the mouthpiece.

[0003] This known aerosol generation system has several drawbacks. It is necessary to prevent "dry heating" or "dry suction," which occurs when the heating element is heated if the supply of liquid aerosol forming matrix to it is insufficient. During operation, it is preferable to maintain a supply of liquid aerosol forming matrix to the heating element so that the heating element remains moist, as this helps ensure satisfactory aerosol generation during user suction. Dry heating can lead to overheating of the heating element and potentially thermal decomposition of the liquid aerosol forming matrix, which can produce undesirable byproducts and unsatisfactory aerosols. Allowing the aerosol generation system to continue operating when no liquid aerosol forming matrix is ​​supplied to the heating element can result in a poor user experience.

[0004] Conversely, it has been found that existing aerosol generation systems may leak the liquid aerosol forming matrix. For example, if the liquid aerosol forming matrix is ​​supplied to the heating element at a rate faster than the rate at which the heating element evaporates, the liquid aerosol forming matrix may leak from one end of the core and leave the system. This wastes the aerosol forming matrix and may contaminate other components of the aerosol generation system. Therefore, leakage of the liquid aerosol forming matrix is ​​undesirable.

[0005] It is desirable to provide a heater assembly in which a liquid aerosol forming matrix is ​​provided for efficient and consistent supply to a heating element.

[0006] It is desirable to provide a heater assembly that reduces or prevents leakage of the liquid aerosol formation matrix. Summary of the Invention

[0007] According to this disclosure, a heater assembly for an aerosol generation system is provided. The heater assembly may include a heating element for evaporating a liquid aerosol forming matrix. The heater assembly may include a porous body for conveying the liquid aerosol forming matrix to the heating element. The porous body may have a liquid absorption surface. The porous body may have a heating surface. The heating element may be located on the heating surface of the porous body. The heating element and the porous body may be integrally formed. The heating element and the porous body may be formed as a single integral piece. The average pore size of the porous body may vary between the liquid absorption surface and the heating surface.

[0008] According to a first aspect of the invention, a heater assembly for an aerosol generation system is provided. The heater assembly includes a heating element for evaporating a liquid aerosol forming matrix. The heater assembly includes a porous body for conveying the liquid aerosol forming matrix to the heating element. The porous body has a liquid absorption surface. The porous body has a heating surface. The heating element is located on the heating surface of the porous body. The heating element and the porous body are integrally formed. The average pore size of the porous body varies between the liquid absorption surface and the heating surface.

[0009] Porous bodies that provide variations in pore size between the liquid-absorbing surface and the heating surface advantageously help control the delivery of the liquid aerosol-forming matrix from its reservoir to the heating element. Specifically, the variation in pore size between the liquid-absorbing surface and the heating surface allows the porous body to provide a consistent supply of aerosol-forming matrix to the heating surface. This advantageously avoids undesirable "dry heating." Furthermore, the porous body of the present invention also advantageously prevents leakage of the liquid aerosol-forming matrix from the heating surface of the porous body.

[0010] Providing a heating element integrally formed with the porous body advantageously offers a more robust and reliable connection between the heating element and the porous body. This can advantageously help improve heat transfer between the heating element and the porous body.

[0011] Integrating the heating element integrally with the porous body also advantageously provides a heating element that is easier and more reliable to manufacture, thus resulting in a more energy-efficient heating element capable of generating more consistent aerosols. This, in turn, can provide users of aerosol generation systems with an improved and more pleasant experience. Such an arrangement can also help reduce the likelihood of users experiencing dry heating or dry suction.

[0012] The advantage of integrally forming the heating element with the porous body is that it helps alleviate manufacturing tolerance issues encountered with core and coil heaters, as well as other arrangements where the heating element is separated from the liquid delivery element. The size and arrangement of the heating element relative to the porous body are also fixed, which helps produce a more consistent aerosol. This is because the heating element is fixed to the porous body, which helps supply the liquid aerosol forming matrix to the heating element. This also helps prevent unwanted heat loss, which helps improve energy efficiency.

[0013] By integrally forming the heating element with the porous body, the resulting aerosol generation system benefits from reduced material requirements. This is because the need for intermediate components that fix the heating element relative to the porous body can be reduced or completely eliminated. Material savings lead to cost savings throughout the aerosol generation system. An additional benefit of the reduced material requirements throughout the aerosol generation system is that it provides a more sustainable and environmentally friendly solution.

[0014] Since the heating element is integrally formed with the porous body, the heating surface of the porous body does not necessarily have to be a clearly defined surface. The porous body and the heating element can be made from a single, integral portion of the porous material. In this case, the heating element can be a portion of the porous material configured to generate heat. As described in more detail below, this can be achieved, for example, by doping a portion of the porous material or by diffusing a conductive material into the porous material. Therefore, the heating surface of the porous body can represent the interface between the portion of the porous material configured to transport a liquid aerosol forming matrix and the portion of the porous material configured to generate heat. Depending on how the heating element is formed, the heating surface of the porous body can be a gradient interface between the portion of the porous material configured to transport a liquid aerosol forming matrix and the portion of the porous material configured to generate heat.

[0015] Porous bodies can have any porosity. The porosity of a porous body can be substantially constant between the liquid-absorbing surface and the heating surface. The porosity of a porous body can vary between the liquid-absorbing surface and the heating surface. Compared to the heating surface, the porosity of the porous body can be greater at the liquid-absorbing surface.

[0016] The porosity of the porous body at the liquid-absorbing surface can be at least 20%. For example, the porosity of the porous body at the liquid-absorbing surface can be at least 30% or at least 40%.

[0017] The porosity of a porous body at the liquid-absorbing surface may not exceed 100%. For example, the porosity of a porous body at the liquid-absorbing surface may not exceed 90%, 80%, 70%, or 60%.

[0018] The porosity of a porous body at the liquid-absorbing surface can range from 20% to 90%. For example, the porosity of a porous body at the liquid-absorbing surface can be between 30% and 80%, between 40% and 70%, or between 40% and 60%. The porosity of a porous body at the liquid-absorbing surface can be approximately 50%.

[0019] The porosity of the porous body at the heated surface can be at least 20%. For example, the porosity of the porous body at the heated surface can be at least 30% or at least 40%.

[0020] The porosity of the porous body at the heated surface may not exceed 100%. For example, the porosity of the porous body at the heated surface may not exceed 90%, 80%, 70%, or 60%.

[0021] The porosity of a porous body at the heated surface can range from 20% to 90%. For example, the porosity of a porous body at the heated surface can be between 30% and 80%, between 40% and 70%, or between 40% and 60%. The porosity of a porous body at the heated surface can be approximately 50%.

[0022] The porous body can have any length. The porous body can have a length of at least 0.5 mm. For example, the porous body can have a length of at least 1 mm, at least 2 mm, at least 3 mm, at least 4 mm, or at least 5 mm.

[0023] Porous bodies may have a length not exceeding 20 mm. For example, porous bodies may have a length not exceeding 10 mm, 9 mm, 8 mm, 7 mm, or 6 mm.

[0024] Porous bodies can have lengths between 0.5 mm and 20 mm. For example, porous bodies can have lengths between 1 mm and 10 mm, between 2 mm and 9 mm, between 3 mm and 8 mm, between 4 mm and 7 mm, or between 5 mm and 6 mm. Porous bodies can also have a length of approximately 5 mm.

[0025] As used herein with reference to this invention, the term "liquid aerosol-forming matrix" refers to a liquid matrix capable of releasing volatile compounds that can form aerosols. These volatile compounds can be released by heating the aerosol-forming matrix.

[0026] As used herein with reference to this invention, the term "heating element" refers to a component that transfers heat energy to the liquid aerosol generation matrix. It should be understood that the electric heating element can be deposited directly on the porous body. It should be understood that the heating element can be part of the same porous material forming the porous body.

[0027] As used herein with reference to the invention, the term "porous body" refers to a component having a plurality of pores, at least some of which are interconnected. A porous body is configured to contain liquid within the plurality of pores. A porous body may comprise a porous material.

[0028] As used herein with reference to the present invention, the term "heating surface" refers to the surface of a porous body that is closest to the heating element or on which the heating element is disposed.

[0029] As used herein with reference to the present invention, the term "liquid-absorbing surface" refers to the surface of a porous body opposite the heating surface. In use, the liquid-absorbing surface may be arranged to receive the liquid aerosol-forming matrix from the liquid storage portion of a reservoir of the liquid aerosol-forming matrix.

[0030] The average pore size of a porous body can vary in any way between the liquid-absorbing surface and the heating surface. The average pore size can vary from relatively large pores at the liquid-absorbing surface to relatively small pores at the heating surface.

[0031] Porous bodies may include an average pore size gradient between a liquid-absorbing surface and a heating surface. This average pore size gradient can be constant or variable.

[0032] The average pore size can vary gradually between the liquid-absorbing surface and the heating surface. For example, the portion of the porous body including the liquid-absorbing surface may have a first average pore size, and the portion of the porous body including the heating surface may include a second average pore size. The first average pore size may be larger than the second average pore size.

[0033] The porous body may have a heating end and a liquid absorption end, with the heating surface disposed at the heating end and the liquid absorption surface disposed at the liquid absorption end. The porous body may have a first average pore diameter at the liquid absorption end and a second average pore diameter at the heating end, wherein the first average pore diameter is larger than the second average pore diameter.

[0034] Porous bodies with a larger average pore size at the liquid absorption end and a smaller average pore size at the heating end particularly facilitate the efficient transfer of the liquid aerosol forming matrix from the liquid absorption end to the heating end of the porous body without allowing leakage. Specifically, the inventors of this invention have discovered that the liquid aerosol forming matrix is ​​transferred from the liquid absorption end to the heating end of the porous body via capillary action. The speed at which the liquid aerosol forming matrix moves through the porous body depends on many factors, including but not limited to the geometry of the pores, the surface tension between the liquid aerosol forming matrix and the porous body, the viscosity of the liquid aerosol forming matrix, the surface tension of the liquid aerosol forming matrix, and the overall geometry of the porous body. The inventors of this invention have discovered the need to balance these factors to provide efficient transfer of the liquid aerosol forming matrix to the heating surface of the porous body while preventing leakage of the liquid aerosol forming matrix.

[0035] First, to ensure effective capillary flow of liquid through the porous body, the capillary pressure must overcome the viscous resistance pressure. Second, to prevent leakage, the inertial force must not overcome the capillary pressure. These two requirements are achieved by providing a porous body with larger pores at the liquid absorption end and smaller pores at the heating end.

[0036] In particular, the inventors of this invention have recognized that the viscosity of the liquid aerosol forming matrix changes with temperature. Specifically, the viscosity of the liquid aerosol forming matrix decreases as its temperature increases. As a result, the viscosity of the liquid aerosol forming matrix decreases as it moves from the liquid absorption surface through the porous body to the heating surface. Since the liquid aerosol forming matrix is ​​transported through the porous body by capillary force, this capillary force needs to overcome the viscous resistance of the liquid. The viscous resistance decreases as the viscosity decreases. As a result, the capillary force required to move the liquid aerosol forming matrix can be reduced towards the heating surface of the porous body while maintaining the same flow rate. Therefore, the average pore size of the porous body can be reduced towards the heating surface without reducing the flow of the liquid aerosol forming matrix through the porous body.

[0037] The porous body may include pores having any pore size. The first average pore size may be at least 1 micrometer. For example, the first average pore size may be at least 2 micrometers, at least 5 micrometers, at least 10 micrometers, at least 25 micrometers, or at least 50 micrometers.

[0038] The first average pore size may not exceed 250 micrometers. For example, the first average pore size may not exceed 200 micrometers, 150 micrometers, 100 micrometers, or 50 micrometers.

[0039] The first average pore size can be between 1 micrometer and 250 micrometers. For example, the first average pore size can be between 2 micrometers and 200 micrometers, between 5 micrometers and 150 micrometers, between 10 micrometers and 100 micrometers, or between 25 micrometers and 50 micrometers.

[0040] The first average pore size can be between 5 micrometers and 200 micrometers. The first average pore size can be between 10 micrometers and 90 micrometers.

[0041] The second average pore size may be at least 1 micrometer. For example, the second average pore size may be at least 2 micrometers, at least 5 micrometers, at least 10 micrometers, at least 25 micrometers, or at least 50 micrometers.

[0042] The second average pore size may not exceed 250 micrometers. For example, the second average pore size may not exceed 200 micrometers, 150 micrometers, 100 micrometers, or 50 micrometers.

[0043] The second average pore size can be between 1 micrometer and 250 micrometers. For example, the second average pore size can be between 2 micrometers and 200 micrometers, between 5 micrometers and 150 micrometers, between 10 micrometers and 100 micrometers, or between 25 micrometers and 50 micrometers.

[0044] The second average pore size can be between 5 micrometers and 200 micrometers. Alternatively, the second average pore size can be between 10 micrometers and 90 micrometers.

[0045] The first average pore diameter at the liquid absorption end of the porous body can be larger than the second average pore diameter at the heating end of the porous body.

[0046] The porous body may comprise a first porous material at the liquid absorption end and a second porous material at the heating end, the first porous material having a first average pore size and the second porous material having a second average pore size.

[0047] In this way, a porous body may include two adjacent porous materials, which have different pore sizes.

[0048] The average pore size of the second porous material can be smaller than that of the first porous material.

[0049] Except that the first porous material and the second porous material have different porosities, the first porous material may comprise the same material as the second porous material. For example, the first porous material and the second porous material may comprise silicon nitride.

[0050] The first porous material can have any length. The second porous material can have any length. The length of the first porous material can be substantially the same as the length of the second porous material. The length of the second porous material can be greater than the length of the first porous material.

[0051] The length of the first porous material can be greater than the length of the second porous material.

[0052] As used herein with reference to the invention, the term "length" refers to the dimension of a component of the heater assembly measured along the longitudinal axis of the heater assembly.

[0053] As used herein with reference to the invention, the term "longitudinal axis" refers to the axis extending between the liquid absorption surface and the heating surface of the porous body of the heater assembly. During use of the heater assembly, the liquid aerosol forming matrix is ​​drawn from the liquid absorption surface of the porous body to the heating surface of the porous body substantially along the longitudinal direction.

[0054] As used herein with reference to the invention, the term "transverse" is used to describe a direction perpendicular to the longitudinal direction.

[0055] As used herein with reference to the invention, the term “width” refers to the maximum dimension of a heater assembly, a component of a heater assembly, or a portion of a heater assembly in the lateral direction.

[0056] The ratio of the length of the first porous material to the length of the second porous material can be at least 1. For example, the ratio of the length of the first porous material to the length of the second porous material can be at least 1.5, at least 2, at least 2.5, at least 3, at least 4, or at least 5.

[0057] The area of ​​the heating surface of a porous body can be substantially the same as the area of ​​the heating element.

[0058] In this way, the heating element can advantageously heat the entire heating surface of the porous body. This can advantageously maximize the aerosolization of the liquid aerosol forming matrix and prevent or reduce leakage of the liquid aerosol forming matrix from the heating surface of the porous body.

[0059] The heating element can be any type of heating element. The heating element can be fluid-permeable.

[0060] As used herein with reference to the present invention, in the context of a heating element, the term "fluid-permeable" means that the liquid aerosol forming matrix can be transferred from one side of the heating element to the other without needing to travel around the heating element.

[0061] It should be understood that for fluid-permeable heating elements, the material used to manufacture the heating element can be fluid-permeable. Alternatively, the material used to manufacture the heating element can be fluid-impermeable, but the structure or arrangement of the heating element can still allow the liquid aerosol forming matrix to be transferred from one side of the heating element to the other.

[0062] The heating element can be an electric heating element. For example, the heating element can be a resistance heating element. The heating element can have any suitable shape or form. Examples of suitable shapes and forms include, but are not limited to, strips, filaments, threads, meshes, flat helical coils, fibers, or fabrics.

[0063] In some preferred embodiments, the heating element is planar. A planar heating element may extend substantially in a plane.

[0064] In some preferred embodiments, the heating element comprises a mesh. The heating element may include an array of filaments forming the mesh. As used herein, the term "mesh" encompasses a grid and array of filaments having spaces therebetween. The term mesh also includes woven and nonwoven fabrics.

[0065] Wires can be formed by etching sheet materials such as foil. This can be particularly advantageous when the heater assembly includes an array of parallel wires.

[0066] If the heating element comprises a web or fabric of silk, the silk can be formed individually and woven together.

[0067] Heating elements may include resistance heating elements. Heating elements may be made of any suitable conductive 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 of ceramic and metallic materials. Such composite materials 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 metal alloys include stainless steel; constantan; nickel-containing alloys, cobalt-containing alloys, chromium-containing alloys, aluminum-containing alloys, titanium-containing alloys, zirconium-containing alloys, hafnium-containing alloys, niobium-containing alloys, molybdenum-containing alloys, tantalum-containing alloys, tungsten-containing alloys, tin-containing alloys, gallium-containing alloys, manganese-containing alloys, and iron-containing alloys; and nickel-, iron-, and cobalt-based superalloys; stainless steel, Iron-aluminum based alloys, and iron-manganese-aluminum based alloys. "[Ti]" is a registered trademark of Titanium Metals. The heating element can be made of stainless steel (e.g., 300 series stainless steels, such as AISI 304, 316, 304L, 316L). In a preferred embodiment, the electric heating element may include one or more of NiCr and TiZr.

[0068] Additionally, the heating element may comprise a combination of the materials described above. This combination of materials can be used to improve control over the resistance of the heating element. For example, a material with high intrinsic resistance may be combined with a material with low intrinsic resistance. This may be advantageous if one material is more beneficial in other aspects, such as price, processability, or other physical and chemical parameters. Advantageously, high resistivity heating allows for more efficient use of battery energy.

[0069] Electrical heating elements can be formed from conductive materials deposited onto a porous body. As used herein, the term "conductive material" refers to a material having a resistivity of 1 x 10⁻² Ωm or less. As used herein, the term "deposition" means the application of a layer or coating, such as in the form of a liquid, plasma, or vapor, through a physical or chemical process, which subsequently condenses or accumulates to form the electrical heating element, rather than simply being laid on or fixed to the porous body as a solid, pre-formed component. In this way, the heating element is integrally formed with the porous body.

[0070] The electric heating element can be directly deposited onto the porous outer surface. In other words, the conductive material forming the electric heating element is deposited onto the porous body, allowing the electric heating element to be in direct contact with the porous body.

[0071] In some instances, the conductive material of the electric heating element can at least partially diffuse into the porous body. As used herein, the term "diffused into the porous body" means that the conductive material (e.g., by extending into the pores of the porous body) is dispersed at the interface between the conductive material and the porous body. This arrangement helps to secure the electric heating element to the porous body and increases the contact between the electric heating element and the porous body to improve heating of the liquid aerosol forming matrix and aerosol delivery. In this way, the heating element is integrally formed with the porous body.

[0072] The conductive material forming the electric heating element can be deposited onto the porous body in any suitable manner. For example, the conductive material can be deposited as a liquid onto the porous body using a dispensing pipette or syringe, or using a fine-tipped transfer device (such as a needle).

[0073] In some instances, at least one heating element comprises a printable conductive material printed on a porous body. In such embodiments, any suitable known printing technique can be used. For example, one or more of screen printing, gravure printing, flexographic printing, and inkjet printing. Such printing processes may be particularly suitable for high-speed production processes.

[0074] Alternatively, the conductive material forming the electric heating element can be deposited onto the porous body using one or more vacuum deposition processes, such as evaporation deposition and sputtering.

[0075] At least one heating element can be formed of any suitable conductive material. In some preferred embodiments, the conductive material includes one or more of metals, conductive polymers, and conductive ceramics.

[0076] Suitable conductive metals include, but are not limited to, aluminum, silver, nickel, gold, platinum, copper, tungsten, and their alloys. In some embodiments, the conductive material comprises metal powder suspended in a binder (such as epoxy resin). In one embodiment, the conductive material comprises a silver-containing epoxy resin.

[0077] Suitable conductive polymers include PEDOT (poly(3,4-ethylenedioxythiophene)), PSS (poly(p-phenylene sulfide)), PEDOT:PSS (a mixture of PEDOT and PSS), PANI (polyaniline), PPY (poly(pyrrole)), PPV (poly(p-phenylacetylene)) or any combination thereof.

[0078] Suitable conductive ceramics include ITO (indium tin oxide), SLT (lanthanum-doped strontium titanate), SYT (yttrium-doped strontium titanate), or any combination thereof.

[0079] Conductive materials may also include one or more additives selected from the group consisting of solvents, curing agents, adhesion promoters, surfactants, viscosity reducers, and aggregation inhibitors. Such additives can, for example, be used to assist in the deposition of conductive materials on the porous outer surface of a porous body, to increase the amount of conductive material diffused into the porous outer surface of the porous body, to reduce the time required for the conductive material to solidify, to increase the level of adhesion between the conductive material and the porous body, or to reduce the amount of suspended particles (such as metal particles or powder) aggregated in the conductive material before being applied to the porous outer surface of the porous body.

[0080] Heating elements can have any length. As mentioned above, the “length” of a heating element can refer to the extension of the heating element along the longitudinal axis between the liquid absorption surface and the heating surface of the porous body of the heater assembly. Since the length of a heating element can be significantly smaller than the “width” of the heater assembly, the “length” of a heating element and similar components can also be referred to as the “thickness” of the heating element.

[0081] The heating element may have a thickness of at least 1 micrometer. The heating element may have a thickness of at least 2 micrometers. The heating element may have a thickness of at least 5 micrometers. The heating element may have a thickness of at least 200 micrometers. The heating element may have a thickness of at least 220 micrometers.

[0082] Heating elements can have a thickness of less than 300 micrometers. Heating elements can have a thickness of less than 250 micrometers. Heating elements can have a thickness of less than 50 micrometers. Heating elements can have a thickness of less than 20 micrometers.

[0083] The heating element can have a thickness between 1 mm and 10 mm. The heating element can have a thickness between 1 mm and 5 mm. The heating element can have a thickness between 2 mm and 5 mm.

[0084] The heating element can have a thickness between 200 micrometers and 300 micrometers. The heating element can have a thickness between 200 micrometers and 250 micrometers. The heating element can have a thickness between 220 micrometers and 300 micrometers.

[0085] The heater assembly may also include a first electrical contact and a second electrical contact connected to the heating element. Each electrical contact may be located on opposite sides of the heating surface of the porous body. The heating element may extend between the electrical contacts. An electrical connection may be formed between the heating elements.

[0086] Electrical contacts can be formed from any suitable material. Examples of materials suitable for use in electrical contacts include, but are not limited to, copper, zinc, silver, and gold.

[0087] In one instance, the first and second electrical contacts can be formed from a conductive material deposited directly onto the heated surface of the porous body.

[0088] The electric heating element can extend between the electrical contacts in a wavy or serpentine manner. This helps increase the length of the heating element in contact with the porous outer surface between the electrical contacts, which helps improve the heating of the liquid aerosol forming matrix.

[0089] Porous bodies can contain any material. Porous bodies can contain any porous material. Porous bodies can contain heat-resistant materials.

[0090] Porous materials may include at least one of oxide ceramic materials, non-oxide ceramic materials, glass ceramic materials, semiconductor materials, glass materials, and polymer materials.

[0091] The porous body may contain at least one of alumina, aluminosilicate, zirconium oxide, silicon carbide, silicon nitride, lithium silicate glass ceramic, silicide materials, and boride materials.

[0092] Porous bodies can comprise inert or biocompatible ceramics. Examples of suitable ceramics include those comprising aluminum oxides, zirconium oxides, silicon oxides, calcium silicates, and calcium phosphates (including hydroxyapatite). Porous bodies can also comprise ceramics containing one or more of Al₂O₃, ZrO₂, SiO₂, and Ca₂SiO₃. In preferred embodiments, porous bodies comprise ceramics containing one or both of SiO₂ and Ca₂SiO₃. The advantage of using ceramic materials is that they are thermally stable at the temperatures where the heater assembly typically operates and generally have a significantly higher thermal decomposition temperature than conventional cores. This helps reduce the risk of generating undesirable byproducts during dry heating.

[0093] The porous body may comprise a capillary material through which a liquid aerosol matrix is ​​transported via capillary action. The porous body may have a fibrous or porous structure. The porous body may include capillary bundles. For example, the porous body may include multiple fibers or threads or other fine-pore tubes. The porous body may include fibers or threads of cotton or treated cotton (e.g., acetylated cotton). Other suitable materials may also be used, such as ceramic- or graphite-based fibrous materials or materials made from spun, drawn, or extruded fibers, such as glass fiber, cellulose acetate, or any suitable heat-resistant polymer.

[0094] Porous bodies can include a plurality of interconnected open pores. Porous bodies can contain capillary materials that transport liquids through the material via capillary action. Porous bodies can have a fibrous or porous structure. Porous bodies can include capillary bundles. For example, a porous body can include a plurality of fibers or threads or other fine-pore tubes. Porous bodies can include fibers or threads of cotton or treated cotton (e.g., acetylated cotton). Other suitable materials can also be used, such as ceramic or graphite-based fibrous materials or materials made from spun, drawn, or extruded fibers, such as glass fibers, cellulose acetate, or any suitable heat-resistant polymer.

[0095] The specific pore size in the porous body of the present invention can be produced using any suitable method. For example, pores in the porous body can be created in a monolithic portion of the material using etching techniques. Alternatively, pore sizes can be produced using controlled sintering processes, sol-gel processes, or phase separation processes. These processes enable the porous body to be provided with pores, which in turn allows the liquid aerosol forming matrix to be transported from the liquid absorption surface to the heating surface.

[0096] Porous materials can be essentially incompressible.

[0097] The pores of a porous body can have any shape. The pores of a porous body can be interconnected. A porous body may include multiple longitudinal pores extending from the liquid absorption surface of the porous body to the heating surface of the porous body.

[0098] In the case of a porous body comprising multiple longitudinal pores, the pore diameter can be the width of the longitudinal pores when measured in the transverse direction.

[0099] As used herein with reference to the invention, the term "transverse" refers to a direction orthogonal to the longitudinal axis.

[0100] Providing longitudinally extended pores can advantageously facilitate the efficient transfer of the liquid aerosol formation matrix from the liquid absorption surface of the porous body to the heating surface of the porous body.

[0101] The porous body may include a longitudinal surface extending between the liquid-absorbing surface and the heating surface. The longitudinal surface may be impermeable to the liquid.

[0102] Providing a liquid-impermeable longitudinal surface can advantageously prevent liquid aerosols from leaking out of the longitudinal surface of the porous body.

[0103] The porous body may include a liquid-impermeable coating disposed on the longitudinal surface of the porous body. Alternatively, the porous body may include longitudinally extending pores that prevent the liquid aerosol forming matrix from reaching the longitudinal surface of the porous body. Alternatively, the pore size at the longitudinal surface of the porous body may be small enough to prevent the liquid aerosol forming matrix from reaching the longitudinal surface of the porous body. Alternatively, the porous body may be inserted into a liquid-impermeable housing, such as a glass tube, to prevent leakage of the liquid aerosol forming matrix.

[0104] The porous body may include longitudinal grooves that extend along the longitudinal surface of the porous body between the liquid absorption surface and the heating surface.

[0105] The longitudinal grooves can extend from the liquid absorption surface of the porous body to its heating surface. Providing longitudinal grooves allows air to be transferred from the liquid absorption surface to the heating surface of the porous body. During use, the longitudinal grooves advantageously guide and deliver air toward the heating surface of the porous body as the user draws air onto the aerosol generation system. As the air passes through the heating surface, it may carry aerosol generated by the heating element before being delivered to the user.

[0106] A porous body may include more than one longitudinal groove. For example, a porous body may include at least two, at least three, at least four, or at least five longitudinal grooves. When a porous body includes more than one longitudinal groove, the longitudinal grooves may be uniformly distributed around the periphery of the porous body.

[0107] Porous bodies can have a substantially constant cross-section. For example, the cross-sectional area of ​​the liquid absorption surface of a porous body can be substantially the same as the cross-sectional area of ​​the heating surface.

[0108] Porous bodies can have any shape. For example, a porous body can be generally cylindrical. In this case, both the liquid absorption surface and the heating surface can be circular. A porous body can also have a regular cuboid shape. In this case, both the liquid absorption surface and the heating surface can be square.

[0109] The liquid absorption surface of a porous body can have an area different from the area of ​​its heating surface. The area of ​​the heating surface of the porous body can be smaller than the area of ​​its liquid absorption surface.

[0110] The ratio of the area of ​​the heating surface of the porous body to the area of ​​the liquid absorption surface of the porous body can be less than or equal to 0.9.

[0111] The ratio of the area of ​​the heating surface of the porous body to the area of ​​the liquid absorption surface of the porous body can be at least 0.1.

[0112] The ratio of the area of ​​the heating surface of the porous body to the area of ​​the liquid absorption surface of the porous body can be between 0.1 and 0.9.

[0113] The area of ​​the liquid absorption surface of a porous body can be smaller than the area of ​​the heating surface of the porous body.

[0114] The ratio of the liquid absorption surface area to the heating surface area of ​​the porous body can be less than or equal to 0.9.

[0115] The ratio of the area of ​​the liquid absorption surface of the porous body to the area of ​​the heating surface of the porous body can be at least 0.1.

[0116] The ratio of the liquid absorption surface area to the heating surface area of ​​the porous body can be between 0.1 and 0.9.

[0117] Heater assemblies with heating surfaces having the same area as the liquid absorption surface may be inefficient because the heat generated by the heater is not used to evaporate the aerosol matrix. Inefficient heater assemblies result in reduced aerosol throughput.

[0118] Advantageously, compared with a heater assembly in which the heating surface has the same area as the liquid absorption surface, providing a porous body in which the heating surface and the liquid absorption surface have different areas can improve the throughput of aerosols generated by the heater assembly.

[0119] For example, in a heater assembly where the area of ​​the heating surface of the porous body is smaller than the area of ​​the liquid absorption surface of the porous body, the heat flow from the heating element toward the liquid absorption surface and then to the liquid storage portion via conduction can be reduced. The relatively small heating surface provides a small heat transfer area through which heat is transferred by conduction from the heating element to the porous body and toward the liquid absorption surface.

[0120] Therefore, reducing heat loss from the heating element to the porous body can improve heating efficiency, as more thermal energy provided by the heating element can be used to evaporate the aerosol-forming matrix. Consequently, porous bodies, with their shape allowing for a smaller heating surface area compared to the liquid absorption surface, can increase the throughput of aerosols generated by the heater assembly.

[0121] For example, in a heater assembly in which the area of ​​the liquid absorption surface of the porous body is smaller than the area of ​​the heating surface of the porous body, the smaller area of ​​the liquid absorption surface can cause a reduction in the heat flow from the heating element to the liquid absorption surface via thermal conduction through the aerosol forming matrix.

[0122] Therefore, reducing the heat flow from the heating surface to the liquid absorption surface can improve heating efficiency, as more thermal energy provided by the heating element can be used to evaporate the liquid aerosol forming matrix. Consequently, a porous structure with a smaller surface area for the liquid absorption surface compared to the heating surface can provide increased heating efficiency, which can increase the throughput of aerosols generated by the heater assembly.

[0123] Improving heating efficiency can reduce the power consumption of heater components during use.

[0124] The area of ​​the heating surface of a porous body can be smaller than the area of ​​its liquid absorption surface. Conversely, the area of ​​the liquid absorption surface of a porous body can be larger than its heating surface.

[0125] Advantageously, when the porous body has a shape that allows the heating surface to have a smaller area than the liquid absorption surface, the heat flow from the heating element toward the liquid absorption surface and then to the liquid storage portion via conduction can be reduced. The relatively small heating surface provides a small heat transfer area through which heat is transferred by conduction from the heating element to the porous body and toward the liquid absorption surface.

[0126] Therefore, reducing heat loss from the heating element to the porous body can improve heating efficiency, as more thermal energy provided by the heating element can be used to evaporate the aerosol-forming matrix. Consequently, porous bodies, with their shape allowing for a smaller heating surface area compared to the liquid absorption surface, can increase the throughput of aerosols generated by the heater assembly.

[0127] Advantageously, the porous structure, with its smaller surface area compared to the liquid absorption surface, reduces the area of ​​the heating surface that is not close enough to the heating element to allow the aerosol-forming matrix to be transported to the heating surface for evaporation. In other words, the size and shape of the heating surface can be more closely matched to the size and shape of the heating element. Therefore, more liquid aerosol-forming matrix can be transported from the liquid absorption surface to the area of ​​the heating surface near the heating element, resulting in greater evaporation of the liquid aerosol-forming matrix at the heating surface. Increased evaporation of the liquid aerosol-forming matrix increases the throughput of aerosols generated by the heater assembly. Furthermore, this arrangement allows for maximizing the power density at the heating surface, which also improves heating efficiency.

[0128] Advantageously, the larger surface area of ​​the liquid absorption surface compared to the heating surface allows the liquid absorption surface to receive a larger volume of liquid aerosol matrix from the liquid storage section. Due to the relatively small area of ​​the heating surface, the flow rate of the liquid aerosol forming matrix to the heating element can be higher than that in the case of a typical heater assembly when the liquid aerosol forming matrix is ​​conveyed through the porous body toward the heating surface. The higher flow rate of the liquid aerosol forming matrix at the heating element can increase the throughput of aerosols generated by the heater assembly.

[0129] The area of ​​the heating surface of a porous body can be larger than the area of ​​its liquid absorption surface. Conversely, the area of ​​the liquid absorption surface of a porous body can be smaller than its heating surface.

[0130] Advantageously, when the porous body has a shape that allows the liquid absorption surface to have a smaller area compared to the heating surface, the smaller area of ​​the liquid absorption surface can cause a reduction in the heat flow from the heating element to the liquid absorption surface via thermal conduction through the aerosol forming matrix. Therefore, reducing the heat flow from the heating surface to the liquid absorption surface can improve thermal efficiency, because more thermal energy provided by the heating element can be used to evaporate the liquid aerosol forming matrix. Thus, a porous body with a shape that allows the liquid absorption surface to have a smaller area compared to the heating surface can provide increased heating efficiency, which can increase the throughput of aerosols generated by the heater assembly.

[0131] Advantageously, the porous body, with its shape allowing the liquid absorption surface to have a smaller area compared to the heating surface, reduces the area of ​​the heating surface that is not close enough to the heating element to allow the aerosol-forming matrix to be transported to the heating surface for evaporation. In other words, the size and shape of the heating surface can be more closely matched to the size and shape of the heating element. Therefore, more liquid aerosol-forming matrix can be transported from the liquid absorption surface and reach the area of ​​the heating surface near the heating element, which may result in more evaporation of the liquid aerosol-forming matrix at the heating surface. Increased evaporation of the liquid aerosol-forming matrix can increase the throughput of aerosols generated by the heater assembly.

[0132] Porous bodies can have any cross-sectional shape. Porous bodies can have rectangular or circular cross-sectional shapes.

[0133] The heating surface of the porous body can have any shape. The heating surface of the porous body can be curved along one or both of a first transverse direction and a second transverse direction, with the first transverse direction being orthogonal to the second transverse direction.

[0134] The heating surface of the porous ceramic body may be convex in one or both of the first and second transverse directions, with the first transverse direction being orthogonal to the second transverse direction.

[0135] This porous ceramic body allows for an increase in the surface area of ​​the heating surface without increasing its width. This can improve the efficiency of aerosol generation systems in forming a matrix from evaporated liquid aerosols, while helping to avoid the need to redesign other components of the aerosol generation system to accommodate the porous ceramic body.

[0136] Providing a heating surface that protrudes along one or both of the first and second lateral directions helps to avoid or minimize the recirculation of airflow adjacent to the heater assembly. In particular, the protruding heating surface helps to avoid or minimize the recirculation of airflow adjacent to the central region of the heater assembly. This can reduce the level of turbulence in the airflow adjacent to the heater assembly. Reducing the level of turbulence in the airflow adjacent to the heater assembly improves the entrainment of vapors of the aerosol-forming matrix in the airflow. This can improve the quality of the aerosols generated by the aerosol generation system.

[0137] Improving vapor entrainment in the airflow of an aerosol generation system can prevent or reduce vapor condensation to form large droplets that form the liquid aerosol matrix. This helps avoid unpleasant and undesirable user experiences.

[0138] Improving vapor entrainment in the airflow through an aerosol generation system can prevent or reduce vapor condensation on the system's internal surfaces. This helps avoid or minimize damage to the aerosol generation system and allows it to function optimally.

[0139] The heating surface of a porous body can be convex in a single transverse direction.

[0140] The heating surface of the porous body can be convex in both the first and second transverse directions.

[0141] Based on the configuration of the heater assembly relative to one or more airflow paths of the aerosol generation system, the heating surface of the porous body may be convex in one or both of a first lateral direction and a second lateral direction. The heater assembly may be configured to minimize the level of turbulence in the airflow adjacent to the heater assembly. For example, it may be advantageous to arrange the heater assembly in the aerosol generation system such that air drawn into the aerosol generation system follows a curved path along at least a portion of the curved surface of the heater assembly.

[0142] The heating element may protrude in one or both of the first and second lateral directions.

[0143] The curvature of the heating element in the first transverse direction can be substantially the same as the curvature of the heating surface of the porous body in the first transverse direction. The curvature of the heating element in the second transverse direction can be substantially the same as the curvature of the heating surface of the porous body in the second transverse direction. The curvature of the heating element in both the first and second transverse directions can be substantially the same as the curvature of the heating surface of the porous body in both the first and second transverse directions, respectively.

[0144] The heater assembly may also include a heat insulation layer having a lower thermal conductivity than the porous body, wherein the heat insulation layer is disposed between the porous body and the heating element and contacts each of the porous body and the heating element, and the heat insulation layer is configured to reduce heat transfer from the heating element to the porous body.

[0145] This arrangement reduces heat loss from the heating element to the porous ceramic body and to the liquid within it. This provides a more efficient heater assembly, allowing for increased user usage and frequency before devices such as batteries run out of power. The inventors estimate that in known devices, approximately one-third of the energy from the heating element is lost through conduction in the porous body and the liquid within it. The remaining two-thirds are used to generate aerosols by heating the liquid aerosol-forming matrix. In the arrangement described herein, these energy losses are reduced. Specifically, the insulation layer reduces heat propagation or conduction from or through the heating element to the porous ceramic body. This reduction in conduction concentrates heat on the heating surface of the porous ceramic body, thereby minimizing heat dissipation and increasing the heating efficiency of the heater assembly. The insulation layer may comprise an insulating material. The insulating material may have a lower thermal conductivity compared to the porous ceramic body. The insulating material may have a higher porosity compared to the porous ceramic body. This has the advantage of providing an insulating layer that is particularly effective in reducing energy loss and is also easy to manufacture.

[0146] The insulation layer may comprise a material with a thermal conductivity of less than 40 W / m·Kelvin. This has the advantage of providing an insulation layer that is effective in reducing energy loss through the porous ceramic body. The insulation layer may also comprise a material with a thermal conductivity of less than 10 W / m·Kelvin. This has the advantage of providing an insulation layer that is particularly effective in reducing energy loss through the porous ceramic body.

[0147] The insulation layer can extend completely between the porous ceramic body and the heating element. This has the advantages of providing a more effective barrier between the heating element and the porous ceramic body, and is therefore particularly effective in reducing energy loss through the porous ceramic body.

[0148] The insulation layer may contain one or more of the following: alumina, zirconium oxide, zirconium oxide with magnesium oxide, glass ceramic, quartz, or porous polymer. The porous polymer may be polyimide.

[0149] The insulation layer may comprise alumina with a thermal conductivity of 20-40 W / m·Kelvin. The insulation layer may also comprise materials with a thermal conductivity of less than 10 W / m·Kelvin, such as zirconium oxide with or without magnesium oxide, glass ceramics, or quartz. The use of alumina, zirconium oxide with or without magnesium oxide, glass ceramics, and quartz is advantageous because these materials are compatible with manufacturing processes involving sintering and therefore make it easier to manufacture heater assemblies with insulation layers comprising one of these materials.

[0150] The insulation layer can have a thickness between 0.1 mm and 2 mm. Insulation layers of this thickness are particularly suitable for reducing energy loss from the heating element to the porous ceramic body. Preferably, the insulation layer has a thickness between 0.5 mm and 1.5 mm. Insulation layers of this thickness are further suitable for reducing energy loss from the heating element to the porous ceramic body.

[0151] As used herein with reference to this invention, the term "thermal insulation" refers to the property of reducing or limiting heat transfer. A component with better thermal insulation will transfer less heat via conduction, convection, or radiation compared to a component with better thermal insulation.

[0152] The heating element may comprise multiple rails or rail sections arranged in parallel. The resistance of the heating element at room temperature can be between 0.5 ohms and 1.5 ohms, preferably between 0.7 ohms and 1.3 ohms, and more preferably 1 ohm. The resistance of the heating element can be matched to the requirements of the control electronics.

[0153] At least two electrically parallel heating rails can have similar or identical resistances. Preferably, all electrically parallel heating rails have similar or identical resistances. The electrically parallel arrangement of heating rails can have different resistances, which is particularly beneficial in heater assemblies where different power levels are generated for different areas of the heating element. For example, this could be to compensate for higher heat losses in the outer portions of the heating element. Thus, heating rails on the exterior or outer portions of the heating element can be designed to have lower resistances (which generate more heat) compared to heating rails in the center of the heating element.

[0154] The heating element may include multiple rails or rail sections. These rails or rail sections may be arranged electrically in parallel. With this parallel arrangement, current flow is split into individual parallel flow paths, which are then recombined.

[0155] The heating element may include a first connecting pad and a second connecting pad. The first or second connecting pad (or the first and second connecting pads) may be configured to allow connection to an external circuit. Orifices or multiple orifices in the heating element may separate each rail or rail section. The heating element may include at least one diverging portion, wherein current is shunt from the first connecting pad into the rail section. The rail section defines an electrical parallel path. The heating element may include a converging portion. In the converging portion, current is combined from the rail section defining the electrical parallel path into the second connecting pad.

[0156] Various arrangements of the electrically parallel rails or rail sections are possible. The heating element may include two, three, four or more rail sections that define the electrically parallel path.

[0157] By arranging the rails or rail sections electrically in parallel, if one rail section is defective, the current can be redistributed and can still flow through the heating element; that is, the electrical connection between the first and second connecting pads remains unbroken. In contrast, in a simple serpentine heater that defines a single electrical path between the first and second connecting pads, if a portion of the serpentine heating element breaks or contains a defect, this can cause an increase in local resistance, leading to increased power dissipation, which in turn increases resistance until the element breaks.

[0158] The inventors have also discovered that electrically parallel tracks or track sections have surprising additional advantages. In such an arrangement, even if one track section breaks, the heating element will still operate advantageously, and can operate advantageously for an initial temporary period, because the breakage of one track or track section will result in a higher energy density on the remaining tracks or track sections. In this case, the same power will still be provided, but in a smaller area, thus increasing the throughput of the aerosol-generating matrix. Such a break, causing an increase in current on the unbroken tracks or track sections, may ultimately affect the user experience. This can be mitigated by using a mechanism that alerts the user that the performance of the heater assembly may be below optimal in the future. Electrically parallel tracks have the advantages of increasing the number of suction and desiccation cycles before the heater completely fails, and potentially increasing the heater life to the life of the device.

[0159] The heating element may include a plurality of tracks or track sections defining a path having at least one bend, the inner edge of which is curved.

[0160] The inner edge of the bend is curved, which has the following advantages: it guides the current to flow more evenly around at least one bend. This reduces current concentration, which in turn limits the formation of hot spots.

[0161] The heating element may include multiple rails or rail sections having a resistivity gradient perpendicular to the current flow at one or more corners, such that the resistivity is higher at the inner portion of the corner and lower at the outer portion. Such a gradient helps to balance the localization of high current density and reduce hotspot formation.

[0162] The heating element may include a plurality of rails or rail sections, the plurality of rails or rail sections being arranged such that at least two of the rails or rail sections are spaced apart by a distance in the range of 150 to 300 micrometers.

[0163] All tracks or track sections can be spaced 200 to 300 micrometers apart from at least one other track section. This has the advantage of providing a particularly efficient heater assembly in which the aerosol-forming matrix is ​​effectively evaporated.

[0164] The heating element and the porous body can be molded into a single integral part.

[0165] This can also help simplify the manufacture of heater assemblies by reducing manufacturing time and providing a more cost-effective solution. It can also advantageously create a tight mechanical connection between the heating element and the porous body.

[0166] The heating element can be a doped portion of a porous body.

[0167] Porous materials can be doped so that the portion of the porous material that serves as the heating element is conductive. Doping porous materials can be advantageous because it avoids altering the porosity of the porous material. This is superior to other known techniques for forming heating elements, which involve depositing heating elements via thin-film or thick-film techniques, which can reduce the properties of the porous material, particularly its porosity. The thickness of the doped portion can range from 5 micrometers to 100 micrometers. The thickness of the doped portion can be increased when the cross-sectional area of ​​the heating element is small or when a higher heating resistance is required. The dopant used to dop the porous material can be an n-type dopant or a p-type dopant. The dopant can be any of, but is not limited to, nitrogen, phosphorus, aluminum, or boron. The interface between the heating element and the porous material may include a portion of the partially doped porous material.

[0168] Porous materials can be doped by ion implantation. Ion implantation involves implanting ions into layers of the host material or involves ion exchange (removing one ion and replacing it with another). Ion implantation can be performed chemically or physically.

[0169] Porous materials can be doped via transmutation. Transmutation is the process of transforming one type of atom already present in a material into another through irradiation with particles such as neutrons or alpha particles. This results in a brief decay process that produces a stable isotope not present in the original material. Transmutation is advantageous because doping occurs directly within the ceramic material and does not require bonding or attachment of additional conductive material. Therefore, transmutation offers a more holistic approach.

[0170] According to another embodiment of this disclosure, a cylinder for an aerosol generation system is provided. The cylinder includes a heater assembly according to the invention. The cylinder also includes a liquid storage portion configured to hold a liquid aerosol forming matrix. The liquid storage portion is disposed at the liquid absorption surface of the porous body.

[0171] The liquid storage section can also be referred to as a reservoir. The liquid storage section can contain the liquid aerosol forming matrix.

[0172] Aerosol-forming matrices can contain both liquid and solid components. Liquid aerosol-forming matrices can contain nicotine. Nicotine-containing liquid aerosol-forming matrices can be nicotine salt matrices. Liquid aerosol-forming matrices can contain plant-based materials. Liquid aerosol-forming matrices can contain tobacco. Liquid aerosol-forming matrices can contain tobacco-containing materials with volatile tobacco aroma compounds that are released from the aerosol-forming matrix upon heating. Liquid aerosol-forming matrices can contain homogenized tobacco materials. Liquid aerosol-forming matrices can contain tobacco-free materials. Liquid aerosol-forming matrices can contain homogenized plant-based materials.

[0173] Liquid aerosol forming matrix may contain one or more aerosol forming agents. An aerosol forming agent is any suitable known compound or mixture of compounds that promotes the formation of a dense and stable aerosol during use and is substantially resistant to thermal degradation at the system's operating temperature. Examples of suitable aerosol forming agents include glycerol and propylene glycol. Suitable aerosol forming agents are well known in the art and include, but are not limited to: polyols such as triethylene glycol, 1,3-butanediol, and glycerol; esters of polyols such as mono, di, or triacetic acids of glycerol; and aliphatic esters of mono, di, or polycarboxylic acids such as dimethyl dodecanoate and dimethyl tetradecanoate. Liquid aerosol forming matrix may include water, solvents, ethanol, plant extracts, and natural or artificial fragrances.

[0174] The liquid aerosol forming matrix may contain nicotine and at least one aerosol forming agent. The aerosol forming agent may be glycerol or propylene glycol. The aerosol forming agent may include both glycerol and propylene glycol. The liquid aerosol forming matrix may have a nicotine concentration between about 0.5% and about 10%, for example, about 2%.

[0175] The liquid storage section can be located at the liquid absorption surface of the porous body. The airflow channel can be located at the heating surface of the porous body. The airflow channel can be adjacent to the heating element. The airflow path can extend through the heating element. The airflow path can be configured to transport aerosols. The cylinder body can be configured such that the airflow passing through the heater assembly entrains the evaporated aerosol to form a matrix.

[0176] The cartridge may have a mouthpiece disposed at the opening end of the cartridge. The mouthpiece may have an aerosol outlet through which the generated aerosol can be inhaled by a user. The cartridge may have a connection end configured to connect the cartridge to an aerosol generating device.

[0177] The cylinder may include an air inlet. The cylinder may include a closed airflow passage from the air inlet to the aerosol outlet. The closed airflow passage may extend from the air inlet, through the heater assembly, to the aerosol outlet. The closed airflow passage may bypass the outer surface of the liquid storage section. Alternatively, the closed airflow passage may pass through the liquid storage section. For example, the liquid storage section may have an annular cross-section defining an internal passage, and the airflow passage may extend through the internal passage of the liquid storage section.

[0178] The cylinder may include a first airflow path extending in a first direction from an air inlet toward a heater assembly. The cylinder may include a second airflow path extending through a heating element and configured to entrain aerosol. The cylinder may include a third airflow path extending in a second direction from the heater assembly to an aerosol outlet. The second direction may be opposite to the first direction. The second airflow path may provide a fluid connection between the first and third airflow paths.

[0179] The cartridge may include a shell. The shell may be formed of a durable material. The shell may be formed of a liquid-impermeable material. The shell may be formed of a moldable plastic material, such as polypropylene (PP) or polyethylene terephthalate (PET) or copolymers such as Tritanium. TM The copolymer is made from three monomers: dimethyl terephthalate (DMT), cyclohexanediol (CHDM), and 2,2,4,4-tetramethyl-1,3-cyclobutanediol (CBDO). The shell of the cylinder may define a liquid storage section or part of a reservoir. The shell may define a liquid storage section. The shell and the liquid storage section may be integrally formed. Alternatively, the liquid storage section may be formed separately from the outer shell and disposed within the outer shell.

[0180] According to another embodiment of this disclosure, an aerosol generation system comprising a cylinder according to the invention is provided.

[0181] The system may also include an aerosol generating device, which includes a power source for supplying power to the heater assembly, and a control circuitry system for controlling the power supply from the power source to the heater assembly. The cylinder is removably coupled to the aerosol generating device.

[0182] The aerosol generation system may also include an air inlet and an aerosol outlet, with the air inlet and aerosol outlet in fluid communication to define the airflow path through the aerosol generation system.

[0183] The heater assembly can be arranged in fluid communication with the airflow path, such that air flows through the heater assembly in the average airflow direction, wherein the heater assembly and the airflow path are arranged such that the angle between the average vapor discharge direction and the average airflow direction is less than 135 degrees.

[0184] According to an example of this disclosure, an aerosol generation system is provided, comprising: a heater assembly according to the invention, an air inlet, and an aerosol outlet, the air inlet and the aerosol outlet being in fluid communication to define an airflow path through the aerosol generation system; wherein the heater assembly is arranged in fluid communication with the airflow path such that air flows through the heater assembly in an average airflow direction, and wherein the heater assembly and the airflow path are arranged such that the angle between the average vapor emission direction and the average airflow direction is less than 135 degrees. The features described herein with respect to the heater assembly according to a first aspect of the invention also apply to the heater assembly of the aerosol generation system.

[0185] The aerosol generation system may include: a heater assembly comprising: a heating element for evaporating a liquid aerosol forming matrix; and a porous body for conveying the liquid aerosol forming matrix to the heating element, the porous body having a liquid absorption surface and a heating surface, the heating element being located on the heating surface of the porous body, the heating element and the porous body being integrally formed, wherein the average pore size of the porous body varies between the liquid absorption surface and the heating surface; wherein the aerosol generation system further includes an air inlet and an aerosol outlet, the air inlet and the aerosol outlet being in fluid communication to define an airflow path through the aerosol generation system; wherein the heater assembly is arranged in fluid communication with the airflow path such that air flows through the heater assembly in an average airflow direction, wherein the heater assembly and the airflow path are arranged such that the angle between the average vapor emission direction and the average airflow direction is less than 135 degrees.

[0186] As used herein with reference to the invention, the term "angle between the average steam discharge direction and the average airflow direction" refers to the angle between the directions of travel of steam discharged from the heater assembly and the airflow within the airflow path. For example, a zero-degree angle would mean that the airflow and steam discharge are traveling in the same direction, while a 180-degree angle would mean that the directions of travel of the airflow and steam discharge are directly opposite each other.

[0187] Advantageously, the heater assembly and airflow path are arranged such that the angle between the average vapor discharge direction and the average airflow direction is less than 135 degrees, and the average airflow direction is not directly opposite the average vapor discharge direction. Therefore, the momentum of the vapor and airflow does not decrease to the same extent as when the average airflow direction is directly opposite the average vapor discharge direction. This reduces the tendency for recirculation and turbulence to occur in the airflow path, and the vapor is less likely to impinge on the inner surfaces of the aerosol generation system. Therefore, aerosol condensation within the aerosol generation system is less likely to occur.

[0188] The average steam discharge direction can be substantially perpendicular to the heating surface. As used herein, the term "substantially perpendicular" means 90 degrees ± 10 degrees, preferably ± 5 degrees.

[0189] The advantage of having the average steam discharge direction substantially perpendicular to the heating surface is that it simplifies orienting the average steam discharge direction relative to the average airflow direction, since the steam will be discharged substantially perpendicular to the heating surface of the porous body. Therefore, the desired angle between the average steam discharge direction and the average airflow direction can be achieved by appropriately angling the heater assembly relative to the airflow in the airflow path (or vice versa).

[0190] The heater assembly and airflow path can be arranged such that the angle between the average steam discharge direction and the average airflow direction is less than 110 degrees, preferably less than 100 degrees.

[0191] The heater assembly and airflow path can be arranged such that the angle between the average vapor discharge direction and the average airflow direction is approximately 90 degrees. This arrangement results in vapor being discharged at an angle substantially perpendicular to the average airflow direction. The average vapor discharge direction has no velocity or directional component relative to the airflow direction, and therefore reduces any momentum loss in the airflow. This reduces the tendency for recirculation and turbulence to occur in the airflow path, and vapor is less likely to impinge on the inner surfaces of the aerosol generation system. Furthermore, vapor entrainment in the airflow is improved. Therefore, aerosol condensation within the aerosol generation system is less likely to occur.

[0192] The heater assembly and airflow path can be arranged such that the angle between the average vapor discharge direction and the average airflow direction is less than 90 degrees. In this arrangement, the average vapor discharge direction has no velocity or directional component relative to the airflow direction, and actually has velocity and directional components in the same direction as the average airflow direction. Therefore, any momentum loss in the airflow is further reduced. This reduces the tendency for recirculation and turbulence to occur in the airflow path, and vapor is less likely to impinge on the inner surfaces of the aerosol generation system. Furthermore, vapor entrainment in the airflow is improved. Therefore, aerosol condensation within the aerosol generation system is less likely to occur.

[0193] The heater assembly and airflow path can be arranged such that the angle between the average steam discharge direction and the average airflow direction is approximately 45 degrees. Alternatively, the heater assembly and airflow path can be arranged such that the angle between the average steam discharge direction and the average airflow direction is less than 45 degrees.

[0194] The heater assembly and airflow path can be arranged such that the average vapor discharge direction and the average airflow direction are substantially the same. In this arrangement, since the average vapor discharge direction and the average airflow direction are the same, there is virtually no loss of airflow momentum. This reduces the tendency for recirculation and turbulence to occur in the airflow path, and vapor is less likely to impinge on the inner surfaces of the aerosol generation system. Furthermore, vapor entrainment in the airflow is improved. Therefore, aerosol condensation within the aerosol generation system is less likely to occur.

[0195] The cross-sectional area of ​​the airflow path in the heater assembly region can be configured such that, during use, the airflow velocity is between 0.1 and 2 m / s, preferably between 0.5 and 1.5 m / s, and more preferably about 1 m / s. This range of airflow velocities has been found to effectively entrain vapors emitted from heating elements of various designs without overcooling the heating elements.

[0196] The aerosol generating device may include a housing. The housing may be elongated. The housing may contain any suitable material or combination of materials. Examples of suitable materials include metals, alloys, plastics, or composites containing one or more of said materials, or thermoplastics suitable for food or pharmaceutical applications, such as polypropylene, polyetheretherketone (PEEK), and polyethylene. Preferably, the material is lightweight and non-brittle.

[0197] The housing of the aerosol generating device may define a cavity or recess for a portion of the receiving cylinder. The aerosol generating device may have a connection end configured to removably connect the aerosol generating device to the cylinder. The connection end may include a cavity or recess for the receiving cylinder.

[0198] The aerosol generating device may have a distal end opposite the connecting end. The distal end may include an electrical connector configured to connect the aerosol generating device to an external power source for charging the aerosol generating device.

[0199] The aerosol generation system may include an air inlet. The air inlet may be located at the interface between the cylinder and the aerosol generation device. The aerosol generation system may include a closed airflow path from the air inlet to the aerosol outlet in the nozzle. The closed airflow path may extend from the air inlet through the heater assembly to the aerosol outlet.

[0200] The aerosol generation system may include a first airflow path extending in a first direction from an air inlet toward a heater assembly. The aerosol generation system may include a second airflow path extending past an electrically heated element and configured to entrain aerosols. The aerosol generation system may include a third airflow path extending in a second direction from the heater assembly to an aerosol outlet. The second direction may be opposite to the first direction. The second airflow path may provide a fluid connection between the first and third airflow paths.

[0201] The power source can be any suitable power source. Preferably, the power source is a DC power source. The power source can be a battery. The battery can be a lithium-based battery, such as a lithium cobalt battery, a lithium iron phosphate battery, a lithium titanate battery, or a lithium polymer battery. The battery can be a nickel metal hydride battery or a nickel-cadmium battery. The power source can be another form of charge storage device, such as a capacitor. The power source can be rechargeable and configured for many charge-discharge cycles. The power source can have a capacity that allows storing enough energy for one or more user experiences of the aerosol generation system; for example, the power source can have sufficient capacity to allow continuous aerosol generation for a period of approximately six minutes (corresponding to the typical time taken to smoke a regular cigarette), or for a period of multiples of six minutes. In another example, the power source can have sufficient capacity to allow a predetermined number of inhalations or discontinuous activation of the aerosol generation system.

[0202] The control circuitry system may include any suitable controller or electrical component. The controller may include memory. Information used to perform the methods described above may be stored in the memory. The control circuitry system may include a microprocessor. The microprocessor may be a programmable microprocessor, a microcontroller, an application-specific integrated circuit (ASIC), or other electronic circuitry capable of providing control. The control circuitry system may be configured to continuously supply power to the heating element after the device is activated, or it may be configured to supply power intermittently, such as on a per-mouth suction basis. Power may be supplied to the heating element in the form of current pulses, for example, by means of pulse width modulation (PWM).

[0203] The control circuitry system may include additional electronic components. For example, in some embodiments, the control circuitry system may include any of a sensor, a switch, or a display element.

[0204] The aerosol generation system may include a suction detector. The suction detector can be configured to detect when a user is inhaling on the aerosol generation system. The suction detector can be any suitable sensor capable of detecting when a user is inhaling on the aerosol generation device. For example, the suction detector can be an airflow sensor. The control circuitry can be configured to supply power to the heating element when the suction detector detects that a user is inhaling on the aerosol generation system.

[0205] The features described in one of the above examples can also be applied to other examples of this disclosure.

[0206] The 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.

[0207] Example Ex1: A heater assembly for an aerosol generation system, the heater assembly including a heating element for evaporating a liquid aerosol forming matrix, and a porous body for conveying the liquid aerosol forming matrix to the heating element, the porous body having a liquid absorption surface and a heating surface, the heating element being located on the heating surface of the porous body, the heating element and the porous body being integrally formed, wherein the average pore size of the porous body varies between the liquid absorption surface and the heating surface.

[0208] Example Ex2. A heater assembly according to Ex1, wherein the porous body has a heating end and a liquid absorption end, the heating surface is disposed at the heating end, and the liquid absorption surface is disposed at the liquid absorption end.

[0209] The porous body has a first average pore diameter at the liquid absorption end and a second average pore diameter at the heating end, wherein the first average pore diameter is larger than the second average pore diameter.

[0210] Example Ex3. The heater assembly according to Ex2, wherein the first average pore size is between 5 micrometers and 200 micrometers.

[0211] Example Ex4. A heater assembly according to Ex2 or Ex3, wherein the porous body comprises a first porous material at the liquid absorption end and a second porous material at the heating end, the first porous material having a first average pore size and the second porous material having a second average pore size.

[0212] Example Ex5. The heater assembly according to Ex4, wherein the length of the first porous material is greater than the length of the second porous material.

[0213] Example Ex6. The heater assembly according to Ex5, wherein the ratio of the length of the first porous material to the length of the second porous material is at least 2.

[0214] Example Ex7. A heater assembly according to any of the preceding examples, wherein the area of ​​the heating surface of the porous body is substantially the same as the area of ​​the heating element.

[0215] Example Ex8. A heater assembly according to any of the preceding examples, wherein the heating element is fluid permeable.

[0216] Example Ex9. A heater assembly according to any of the preceding examples, wherein the porous body comprises at least one of oxide ceramic material, non-oxide ceramic material, glass ceramic material, semiconductor material, glass material and polymer material.

[0217] Example Ex10. A heater assembly according to any of the preceding examples, wherein the porous body comprises at least one of alumina, aluminosilicate, zirconium oxide, silicon carbide, silicon nitride, lithium aluminosilicate glass ceramic, silicide material, and boride material.

[0218] Example Ex11. A heater assembly according to any of the preceding examples, wherein the porous body includes a plurality of longitudinal pores extending from the liquid absorption surface of the porous body to the heating surface of the porous body.

[0219] Example Ex12. A heater assembly according to any of the preceding examples, wherein the porous body includes a longitudinal surface extending between the liquid-absorbing surface and the heating surface, the longitudinal surface being impermeable to the liquid.

[0220] Example Ex13. The heater assembly according to Ex12 further includes at least one longitudinal groove extending along the longitudinal surface of the porous body between the liquid absorption surface and the heating surface.

[0221] Example Ex14. A heater assembly according to any of the preceding examples, wherein the liquid absorption surface of the porous body has an area different from the area of ​​the heating surface of the porous body.

[0222] Example Ex15. A heater assembly according to any of the preceding examples, wherein the area of ​​the heating surface of the porous body is smaller than the area of ​​the liquid absorption surface of the porous body.

[0223] Example Ex16. A heater assembly according to any of the preceding examples, wherein the ratio of the area of ​​the heating surface of the porous body to the area of ​​the liquid absorption surface of the porous body is less than or equal to 0.9.

[0224] Example Ex17. A heater assembly according to any of the preceding examples, wherein the ratio of the area of ​​the heating surface of the porous body to the area of ​​the liquid absorption surface of the porous body is at least 0.1.

[0225] Example Ex18. A heater assembly according to any of the preceding examples, wherein the ratio of the area of ​​the heating surface of the porous body to the area of ​​the liquid absorption surface of the porous body is between 0.1 and 0.9.

[0226] Example Ex19. A heater assembly according to any of the preceding examples, wherein the porous body has a rectangular cross-sectional shape or a circular cross-sectional shape.

[0227] Example Ex20. A heater assembly according to any of the preceding examples, wherein the heating surface of the porous body is curved along one or both of a first lateral direction and a second lateral direction, the first lateral direction being orthogonal to the second lateral direction.

[0228] Example Ex21. A heater assembly according to any of the preceding examples, wherein the heating surface is convex in one or both of the first lateral direction and the second lateral direction.

[0229] Example Ex22. A heater assembly according to any of the foregoing examples further includes a heat insulation layer having a lower thermal conductivity than the porous ceramic body, wherein the heat insulation layer is disposed between the porous ceramic body and the heating element and contacts each of the porous ceramic body and the heating element, and the heat insulation layer is configured to reduce heat transfer from the heating element to the porous ceramic body.

[0230] Example Ex23. A heater assembly according to Ex22, wherein the insulation layer comprises an insulation material having a lower thermal conductivity than the porous ceramic body.

[0231] Example Ex24. A heater assembly according to Ex22 or Ex23, wherein the insulation layer comprises a material having a thermal conductivity of less than 40 W / m·Kelvin.

[0232] Example Ex25. A heater assembly according to any one of Examples 22 to 24, wherein the insulation layer comprises a material having a thermal conductivity of less than 10 W / m·Kelvin.

[0233] Example Ex26. A heater assembly according to any one of Examples 22 to 25, wherein the insulation layer comprises an insulation material having a higher porosity than the porous ceramic body.

[0234] Example Ex27. A heater assembly according to any of the preceding examples, wherein the heating element includes a track defining a path across a heating surface of a porous ceramic body.

[0235] Example Ex28. A heater assembly according to any of the preceding examples, wherein the heating element comprises a plurality of rails or rail portions, the plurality of rails or rail portions being arranged such that at least two of the plurality of rails or rail portions are spaced apart by a distance in the range of 200 to 300 micrometers.

[0236] Example Ex29. A heater assembly according to any of the preceding examples, wherein the heating element comprises a plurality of rails or rail sections arranged in parallel.

[0237] Example Ex30. A heater assembly according to any of the preceding examples, wherein the heating element includes a plurality of tracks or track portions defining a path having at least one bend, the inner edge of the bend being curved.

[0238] Example Ex31. A heater assembly according to any of the preceding examples, wherein the heating element and the porous body are molded as a single integral part.

[0239] Example Ex32. A heater assembly according to any of the preceding examples, wherein the heating element is a doped portion of the porous body.

[0240] Example Ex33. A cylinder for an aerosol generation system, the cylinder comprising a heater assembly according to any of the foregoing examples; and a liquid storage portion configured to hold a liquid aerosol forming matrix; wherein the liquid storage portion is disposed at the liquid absorption surface of the porous body.

[0241] Example Ex34. An aerosol generation system comprising: a cylinder according to Ex33; and an aerosol generation apparatus including a power source for supplying power to the heater assembly, and a control circuit system for controlling the power supply from the power source to the heater assembly; wherein the cylinder is removably coupled to the aerosol generation apparatus.

[0242] Example Ex35. An aerosol generation system according to Ex34 further includes an air inlet and an aerosol outlet, the air inlet being in fluid communication with the aerosol outlet to define an airflow path through the aerosol generation system; wherein the heater assembly is arranged in fluid communication with the airflow path such that air flows through the heater assembly in an average airflow direction, wherein the heater assembly and the airflow path are arranged such that the angle between the average vapor emission direction and the average airflow direction is less than 135 degrees. Attached Figure Description

[0243] The examples will now be described further with reference to the accompanying drawings, in which:

[0244] Figure 1 A perspective view of the first heater assembly according to the present invention is shown.

[0245] Figure 2 A perspective view of the second heater assembly according to the present invention is shown.

[0246] Figure 3 A perspective view of the third heater assembly according to the present invention is shown.

[0247] Figure 4 A plan view along the longitudinal axis of the third heater assembly according to the invention is shown.

[0248] Figure 5 A plan view along the transverse axis of the third heater assembly according to the invention is shown.

[0249] Figure 6 A plan view along the longitudinal axis of the fourth heater assembly according to the invention is shown.

[0250] Figure 7 A plan view along the transverse axis of the fourth heater assembly according to the invention is shown.

[0251] Figure 8 A portion of the heating surface of the heater assembly is shown.

[0252] Figure 9 A portion of the heating surface of a heater assembly according to the invention is shown, and

[0253] Figure 10 A cross-sectional schematic diagram of the aerosol generation system according to the present invention is shown. Detailed Implementation

[0254] Figure 1 The heater assembly 100 shown is intended for use in an aerosol generation system. The heater assembly 100 includes a heating element 120 for evaporating a liquid aerosol forming matrix, and a porous body 110 for conveying the liquid aerosol forming matrix to the heating element 120. The porous body 110 includes a liquid absorption surface 111 and a heating surface 112. The heating element 120 is located on the heating surface 112.

[0255] exist Figure 1 In the example shown, the porous body 110 is cylindrical and formed of sintered ceramic. The porous body 110 is formed of silicon carbide. The porous body 110 includes open pores. The open pores are longitudinal pores that generally extend from the liquid absorption surface 111 to the heating surface 112 of the porous body. The pore size of the pores in the porous body 110 varies between the liquid absorption surface 111 and the heating surface 112.

[0256] The porous body 110 includes a heating end and a liquid absorption end. A heating surface 112 is disposed at the heating end, and a liquid absorption surface 111 is disposed at the liquid absorption end. The porous body includes a first average pore diameter at the liquid absorption end and a second average pore diameter at the heating end. The first average pore diameter is larger than the second average pore diameter.

[0257] The first pore size at the liquid absorption end is approximately 150 micrometers. The second pore size at the heating end is approximately 20 micrometers. The pore size varies linearly between the first and second pore sizes to provide a pore size gradient between the liquid absorption end and the heating end of the porous body 110.

[0258] The pore structure and pore size gradient in the porous body 110 are achieved by etching pores in a portion of silicon carbide.

[0259] The heating element 120 is a resistance heating element, comprising tracks arranged in a serpentine manner on the heating surface 112 of the porous body 110. The serpentine arrangement of the resistance heating element tracks allows fluid to pass between adjacent portions of the resistance heating element. The distance between adjacent parallel portions of the resistance heating element tracks is 250 micrometers. In this manner, the resistance heating element can be described as fluid-impermeable. The resistance heating element includes a conductive material deposited on the heating surface 112 of the porous body 110. The conductive material includes stainless steel.

[0260] The porous body 110 also includes a longitudinal surface 113 extending between the liquid-absorbing surface 111 and the heating surface 112. The longitudinal surface 113 includes a liquid-impermeable coating.

[0261] Figure 2 The heater assembly 200 shown includes, with Figure 1 The heater assembly 100 shown has most of the same features, and the same reference numerals are used to refer to the same features. Figure 2 The heater assembly 200 shown is different from Figure 1 The heater assembly 100 shown includes a first porous material 121 and a second porous material 122. The first porous material 121 is disposed at the liquid absorption end of the porous body 110. The second porous material 122 is disposed at the heating end of the porous body 110. The average pore size of the first porous material 121 is larger than the average pore size of the second porous material 122. The average pore size of the first porous material 121 is substantially constant across the first porous material 121. The average pore size of the second porous material 122 is substantially constant across the second porous material 122. In this way, unlike... Figure 1 In the embodiments, Figure 2 The heater assembly 150 does not include a gradient aperture between the liquid absorption surface 111 and the heating surface. Alternatively, Figure 2 The heater assembly 200 includes a gradual change in average pore size at the interface between a first porous material 121 and a second porous material 122. The first porous material 121 has an average pore size of approximately 150 micrometers. The second porous material 122 has an average pore size of approximately 20 micrometers.

[0262] Figure 3The heater assembly 300 shown includes a... Figure 1 The heater assembly 100 shown has most of the same features, and the same reference numerals are used to refer to the same features. Figure 3 The heater assembly 300 shown is different from Figure 1 The heater assembly 100 shown has a convex heating surface 112 that is curved in both a first lateral direction and a second lateral direction, with the first lateral direction orthogonal to the second lateral direction.

[0263] Figure 4 and Figure 5 The heater assembly 400 shown includes, with Figure 1 The heater assembly 100 shown has most of the same features, and the same reference numerals are used to refer to the same features. Figure 4 A plan view of the heater assembly 400 as viewed along the longitudinal direction toward the heating surface 112 is shown. Figure 5 A plan view of the heater assembly 400 as viewed in the lateral direction is shown. Figure 4 and Figure 5 The heater assembly 400 shown is different from Figure 1 The heater assembly 100 shown has a larger area for the liquid absorption surface 111 of the porous body 110 than for the heating surface 112. Both the liquid absorption surface 111 and the heating surface 112 are circular. In this way, the porous body 110 of the heater assembly 400 has a truncated conical shape.

[0264] Figure 4 and Figure 5 The heater assembly 400 shown is further different Figure 1 The heater assembly 100 shown is configured such that the heater element 120 is a mesh of conductive material integrally formed with the porous body 110.

[0265] Figure 6 and Figure 7 The heater assembly 500 shown includes, with Figure 1 The heater assembly 100 shown has most of the same features, and the same reference numerals are used to refer to the same features. Figure 6 A plan view of the heater assembly 500 as viewed along the longitudinal direction toward the heating surface 112 is shown. Figure 6 A plan view of the heater assembly 500 as viewed in the lateral direction is shown. Figure 6 and Figure 7 The heater assembly 500 shown is different from Figure 1The heater assembly 100 shown has a larger area for the liquid absorption surface 111 of the porous body 110 than for the heating surface 112. Both the liquid absorption surface 111 and the heating surface 112 are square. In this way, the porous body 110 of the heater assembly 500 has a truncated pyramidal shape. The longitudinal surface 113 of the porous body 110 is divided into four equal-sized surfaces.

[0266] The porous body 110 of the heater assembly 500 also includes a plurality of longitudinal grooves 510. Each of four equal-sized portions of the longitudinal surface 113 includes a longitudinal groove 510. Each of the longitudinal grooves 510 extends from the liquid-absorbing surface 111 to the heating surface 112. The longitudinal grooves 510 allow air carrying aerosols generated at the heating surface 113 to be transferred along the longitudinal surface 113 of the porous body 110 to the liquid-absorbing surface 111 of the porous body 110.

[0267] Figure 8 and Figure 9 A schematic diagram of the current flow 800 around the corner of the track surrounding the heating element 120 is shown.

[0268] Figure 8 This is a schematic diagram of current flow 800 around a known heating element 120, where the track portion defines a path with bends, the inner edges of which have sharp corners. In such a track, the current flow, depicted by arrow 800 following the path of least resistance, is concentrated (i.e., the current density increases). This concentration occurs at the inner edges of the corners. Current concentration can increase local temperature and can lead to hot spots at the corners. Hot spots are detrimental because they can affect the efficiency and reliability of the heating element. Hot spots still occur even though the local resistivity of the heater track material may increase due to the increased local temperature (which directs current flow to a lower-resistance path).

[0269] Figure 9 This is a schematic diagram of the current flow 800 around the heating element 120 according to the invention, wherein the track portion defines a path with a bend, the inner edge of which is curved. In such a track, the current flow 800 does not form localized hot spots.

[0270] and Figure 8 Compared to the orbital shape shown, as Figure 9The current flow 800 in the smoother, curved section of the heating track shown remains more uniformly distributed across the heating track, as depicted by the dashed arrow 800. The current flow 800 is guided to flow more evenly to avoid current concentration at any point. This, in turn, limits hot spot formation. The heater track may have a resistivity gradient perpendicular to the current flow in one or more corners, such that the resistivity is higher in the inner portion of the corner and lower in the outer portion. Such a gradient helps to balance the localization of high current density and reduce hot spot formation.

[0271] Figure 10 This is a schematic diagram of the interior of an aerosol generation system 200 according to an embodiment of the present disclosure. The aerosol generation system 200 includes two main components: a cartridge 300 and a main body or aerosol generation device 400. The cartridge 300 is removably connected to the aerosol generation device 400. The aerosol generation device 400 includes a device housing 401 that houses a power source (in this example, a rechargeable lithium-ion battery) in the form of a battery 402 and a control circuitry system 403. The aerosol generation system 200 is portable and has a size comparable to a conventional cigar or cigarette. A mouthpiece is disposed at the opening of the cartridge 300.

[0272] The cylinder 300 includes a cylinder housing 304 that houses the heater assembly 100 and a liquid reservoir or liquid storage section 301 for holding the liquid aerosol forming matrix. The liquid aerosol forming matrix is ​​conveyed downward from the liquid absorption surface 111 through a porous body to the heating element, and when power is supplied to the heating element, the evaporated aerosol forming matrix is ​​discharged from the heating surface 112.

[0273] The cylinder 300 includes one or more air inlets 302 formed in a cylinder housing 304 at locations along the length of the cylinder 300. An aerosol outlet 305 is located in a mouthpiece at the opening end of the cylinder 300. The one or more air inlets 302 are in fluid communication with the aerosol outlet 305 to define an airflow path through the cylinder 300 of the aerosol generation system 200. The airflow path flows from the one or more air inlets 302 to the heater assembly 100 in an airflow passage. The heater assembly 100 is arranged in fluid communication with the airflow path in the airflow passage. Air enters the one or more air inlets 302 and flows through the airflow passage through the heater assembly 100 in the average airflow direction.

[0274] exist Figure 4 In this example, the liquid storage section 301 has an annular cross-section and is arranged around a centrally sealed aerosol channel 303. Once the airflow path reaches the heater assembly 100, the airflow path turns upward around the side of the heater assembly 100 and flows through the aerosol channel to the aerosol outlet 305.

[0275] The aerosol generation system 200 is configured to allow a user to inhale or puff onto the mouthpiece of the cartridge to draw aerosol into their mouth through the aerosol outlet 305. In operation, when the user inhales onto the mouthpiece, air is drawn in through one or more air inlets 302, along an airflow path through an airflow channel, past and around the heater assembly 100, and along an airflow path through an aerosol channel 303 to the aerosol outlet 305. When the system is activated, a control circuit system 403 controls the power supply from the battery 402 to the cartridge 300. This, in turn, controls the amount and nature of the vapor produced by the heater assembly 100. The control circuit system 403 includes an airflow sensor (not shown) and supplies power to the heater assembly 100 when the airflow sensor detects a user inhaling. This type of control arrangement has long been used in aerosol generation systems such as inhalers and electronic cigarettes. When the user inhales onto the mouthpiece of the cartridge 300, the heater assembly 100 is activated and generates vapor entrained in the airflow path. The vapor is cooled within the airflow path to form an aerosol, which is then drawn into the user's mouth through the aerosol outlet 305.

Claims

1. An aerosol generation system, comprising: Heater assembly, the heater assembly comprising: Heating elements for evaporating liquid aerosols to form a matrix, and A porous body for conveying the liquid aerosol forming matrix to the heating element, the porous body having a liquid absorption surface and a heating surface. The heating element is located on the heating surface of the porous body, and the heating element and the porous body are integrally formed. The average pore size of the porous body varies between the liquid absorption surface and the heating surface; The aerosol generation system further includes an air inlet and an aerosol outlet, the air inlet and the aerosol outlet being in fluid communication to define the airflow path through the aerosol generation system; The heater assembly is arranged in fluid communication with the airflow path such that air flows through the heater assembly in the average airflow direction, wherein the heater assembly and the airflow path are arranged such that the angle between the average vapor discharge direction and the average airflow direction is less than 135 degrees.

2. The aerosol generation system according to claim 1, wherein the porous body of the heater assembly has a heating end and a liquid absorption end, the heating surface is disposed at the heating end, and the liquid absorption surface is disposed at the liquid absorption end. The porous body has a first average pore diameter at the liquid absorption end and a second average pore diameter at the heating end, wherein the first average pore diameter is larger than the second average pore diameter.

3. The aerosol generation system according to claim 2, wherein the first average pore size is between 5 micrometers and 200 micrometers.

4. The aerosol generation system according to claim 2 or claim 3, wherein the porous body comprises a first porous material at the liquid absorption end and a second porous material at the heating end, the first porous material having the first average pore size, and the second porous material having the second average pore size.

5. The aerosol generation system according to any of the preceding claims, wherein the area of ​​the heating surface of the porous body is smaller than the area of ​​the liquid absorption surface of the porous body.

6. The aerosol generation system according to any of the preceding claims, wherein the ratio of the area of ​​the heating surface of the porous body to the area of ​​the liquid absorption surface of the porous body is less than or equal to 0.

9.

7. The aerosol generation system according to any of the preceding claims, wherein the ratio of the area of ​​the heating surface of the porous body to the area of ​​the liquid absorption surface of the porous body is at least 0.

1.

8. The aerosol generation system according to any of the preceding claims, wherein the ratio of the area of ​​the heating surface of the porous body to the area of ​​the liquid absorption surface of the porous body is between 0.1 and 0.

9.

9. The aerosol generation system according to any of the preceding claims, wherein the heating surface of the porous body is curved along one or both of a first transverse direction and a second transverse direction, the first transverse direction being orthogonal to the second transverse direction.

10. The aerosol generation system according to any of the preceding claims, wherein the heating surface is convex in one or both of the first and second lateral directions.

11. The aerosol generation system according to any of the preceding claims, further comprising a heat insulation layer having a lower thermal conductivity than the porous body, wherein the heat insulation layer is disposed between the porous ceramic body and the heating element and contacts each of the porous ceramic body and the heating element, and the heat insulation layer is configured to reduce heat transfer from the heating element to the porous ceramic body.

12. The aerosol generation system according to any of the preceding claims, wherein the heating element comprises a plurality of tracks or track sections arranged in parallel.

13. The aerosol generation system according to any of the preceding claims, wherein the heating element and the porous body are molded as a single integral part.

14. The aerosol generation system according to any one of claims 1 to 10, wherein the heating element is a doped portion of the porous body.

15. The aerosol generation system according to any preceding claim, comprising a cylinder, wherein the heater assembly is a component of the cylinder, and wherein the cylinder further comprises a liquid storage portion configured to hold a liquid aerosol forming matrix; wherein the liquid storage portion is disposed at the liquid absorption surface of the porous body of the heater assembly.

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