Heater assembly including thermal insulation layer

Abstract

A heater assembly (100) for an aerosol-generating device, the heater assembly (100) comprising: a heating element (110) for vaporizing a liquid aerosol-forming substrate; a porous body (130) for delivering the liquid aerosol-forming substrate to the heating element; and a thermal insulation layer (120) having a lower thermal conductivity than the porous body (130), where the thermal insulation layer (120) is disposed between the porous body (130) and the heating element (110) and in contact with each of the porous body and the heating element, and the thermal insulation layer (120) is configured to reduce heat transfer from the heating element (110) to the porous body (130), where the porous body (130) includes a porous ceramic body or a porous glass body, and wherein the heating element forms a film across the thermal insulation layer.

Description

Technical Field

[0001] This disclosure relates to a heater assembly for an aerosol generating apparatus. In particular, but not limited to, this disclosure relates to a heater assembly for a handheld, electrically operated aerosol generating apparatus for heating an aerosol forming matrix to generate an aerosol and for delivering the aerosol to a user's mouth. This disclosure also relates to an apparatus including a heater assembly, and a cylinder including a heater assembly. 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 reservoir, or replaceable cartridge, attached to the device. The reservoir includes a liquid aerosol-forming matrix capable of releasing volatile compounds when heated. The device typically also includes a heater for heating the liquid aerosol-forming matrix. In known aerosol-generating 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 negative pressure is applied at the mouthpiece, an electric current passes through the heating element, thereby heating it by resistance heating 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] Such known aerosol generation systems have several drawbacks. For example, they can be difficult to manufacture with consistent manufacturing tolerances, which can lead to inconsistent vapor production and aroma generation. Inconsistent manufacturing tolerances can also affect heat transfer from the heating element to the core, thus reducing the energy efficiency of such devices. They can also experience “dry heating” or “dry suction,” which can result in a poor user experience, occurring when the heating element is heated with insufficient liquid aerosol-forming matrix supplied to it.

[0004] A known aerosol generation system has a ceramic body and a heating element, to which electricity is supplied via electrical contacts. Liquid is supplied from a liquid reservoir to the heating element through pores within the ceramic body. In this known aerosol generation system, low thermal efficiency is caused by energy losses in the heating element. In this system, energy is lost from the heating element to the ceramic body and to the liquid within the ceramic body. These energy losses increase the energy required during use. These energy losses also reduce the amount of energy the device can use before its battery needs to be recharged or replaced. Summary of the Invention

[0005] There is a need to provide a heater assembly with higher energy efficiency. There is also a need to provide a heater assembly that increases the amount of energy the device can use before the battery needs to be recharged or replaced.

[0006] According to an embodiment of this disclosure, a heater assembly for an aerosol generation apparatus 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 heater assembly may include a thermal insulation layer. The thermal insulation layer may have a lower thermal conductivity than the porous body. The thermal insulation layer may be disposed between the porous body and the heating element. The thermal insulation layer may contact each of the porous body and the heating element. The thermal insulation layer may be configured to reduce heat transfer from the heating element to the porous body. The porous body may include a porous ceramic body or a porous glass body.

[0007] According to an embodiment of this disclosure, a heater assembly for an aerosol generation apparatus 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 heater assembly includes a heat-insulating layer having a lower thermal conductivity than the porous body. The heat-insulating layer is disposed between the porous body and the heating element. The heat-insulating layer is in contact with each of the porous body and the heating element. The heat-insulating layer is configured to reduce heat transfer from the heating element to the porous body. The porous body includes a porous ceramic body or a porous glass body.

[0008] This arrangement reduces heat loss from the heating element to the porous 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 toward the porous body. This reduction in conduction concentrates heat on the heating surface of the porous body, thereby minimizing heat dissipation and increasing the heating efficiency of the heater assembly.

[0009] As used herein, the term "aerosol generating apparatus" refers to an apparatus that interacts with a liquid aerosol forming matrix to generate aerosols.

[0010] As used herein, the terms "tube" and "aerosol generation tube" refer to a component that interacts with a liquid aerosol forming apparatus to generate aerosols. An aerosol generation tube contains or is configured to contain a liquid aerosol forming matrix.

[0011] As used herein, 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.

[0012] As used herein, the term "porous" refers to a component having multiple pores. At least some of the pores are open pores. At least some of the pores are interconnected, allowing liquid to pass through the porous component.

[0013] As used herein, the term "porous body" refers to a component having a plurality of pores. At least some of the pores are open pores. At least some of the pores are interconnected, allowing liquid to pass through the porous component. The porous body is configured to contain liquid within the plurality of pores.

[0014] As used herein, the term "heating element" refers to a component that transfers heat energy to the liquid aerosol forming matrix.

[0015] As used in this article, the term "insulation" refers to the property of reducing or limiting heat transfer. A better-insulated component will transfer less heat via conduction, convection, or radiation compared to a better-insulated component.

[0016] The heating element can form a membrane across the insulation layer.

[0017] The insulation layer may comprise an insulating material. The insulating material may have a lower thermal conductivity compared to porous materials. The insulating material may also have a higher porosity compared to porous materials. This offers the advantages of providing an insulation layer that is particularly effective in reducing energy loss and is easy to manufacture.

[0018] 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 structure. 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 structure.

[0019] The insulation layer can extend completely between the porous body and the heating element. This has the advantages of providing a more effective barrier between the heating element and the porous body, and is therefore particularly effective in reducing energy loss through the porous body.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] Porous bodies may include porous ceramic bodies or porous glass bodies. Porous bodies may comprise porous materials with open pores. Multiple open pores may be interconnected to provide a fluid path for the aerosol-generating liquid to pass through the porous body. Porous bodies may comprise materials that do not chemically interact with the liquid aerosol forming matrix. Porous materials may have a porosity between 20% and 80%. Porous bodies may have flat or curved surfaces. Porous bodies may have geometric shapes. Porous bodies may be cubic or cuboid in shape, or they may have a disk or cylinder shape, or any combination of these shapes. Porous bodies may comprise or be composed of materials with low thermal conductivity. Porous bodies may comprise or be composed of non-conductive materials. Porous bodies may comprise polymeric or ceramic materials. Porous bodies may include cotton. The porous body may comprise porous ceramics, such as, but not limited to, Al₂O₃, ZrO₂, Si₃N₄, SiC, Ti₃AlC₂, BN, AlN, SiO₂, MgO, mica, diatomaceous earth, silicates, silicides, borides, glass, or any combination of these materials. The porous body may comprise aluminum nitride or silicon carbide. Aluminum nitride and silicon carbide typically have relatively high thermal conductivity of approximately 100–200 W / m·Kelvin. In sintered form, aluminum nitride and silicon carbide may have thermal conductivity less than 100 W / m·Kelvin.

[0024] Porous bodies can be constructed from monolithic or hybrid materials. They can be built from different parts attached to each other. These different parts can contain or be composed of different materials and can have different morphologies, topologies, and properties. Porous bodies can have a thickness such that heat loss through conduction to the liquid reservoir is negligible. The thickness of a porous body can depend on the materials it is made of and the thermal properties of the liquid it contains. Porous bodies can have a thickness between 0.5 mm and 10 mm. Porous bodies can contain electrically insulating materials.

[0025] The heating element may be disposed on the insulation layer. The heating element may be attached to the insulation layer. The heating element may be attached to a porous body through the insulation layer. The heating element may be attached to the porous body, wherein the insulation layer is between the heating element and the porous body. The heating element may contain or be composed of a conductive material. The heating element may contain or be composed of a metal, such as, but not limited to, stainless steel, Ni-Cr alloys, NiCrAlY alloys, FeCrAl alloys (e.g., "Kanthal"), FeCrAlY alloys, Fe3Al alloys, Ni3Al alloys, NiAl alloys, and CuNi alloys. The heating element may contain or be composed of an electroceramic, such as, but not limited to, MoSi2, doped SiC, indium tin oxide (ITO), lanthanum-doped strontium titanate (SLT), yttrium-doped strontium titanate, or any combination of these materials. The heating element may contain an impermeable material. When electricity is supplied, the heating element generates heat through the Joule effect.

[0026] Heating elements can be deposited or patterned using thick-film technologies such as screen printing, inkjet printing, aerosol jet printing, and LDS (laser direct forming). Heating elements can also be deposited or patterned using thin-film technologies such as PVD (physical vapor deposition, e.g., evaporation, sputtering) or CVD (chemical vapor deposition) or similar technologies. The resistance of the heating element at room temperature can be between 0.5 ohms and 1.5 ohms, between 0.7 ohms and 1.3 ohms, or preferably 1 ohm.

[0027] The heating element can be a porous heating element.

[0028] The heating element may extend to cover an area of ​​the heating surface of the insulation layer. The heating element may extend to cover a majority of the heating surface of the insulation layer. The heating element may extend to cover at least half of the heating surface of the insulation layer. Preferably, the heating element extends to cover at least two-thirds of the heating surface of the insulation layer. More preferably, the heating element extends to cover at least three-quarters of the heating surface of the insulation layer. Even more preferably, the heating element extends to cover all of the heating surface of the insulation layer.

[0029] A template can be added to the heating element material, which is then removed by sintering to form a porous structure, thereby improving liquid evaporation. The heating element may have microstructures indicating that they have been fabricated using a template, which has been removed by sintering to form a porous structure.

[0030] The heating element may be disposed on at least one surface of the porous body. The heating element may cover at least one surface of the porous body. The heating element may enclose the porous body. The porous heating element may be planar or may have any suitable shape.

[0031] In known serpentine heating elements, failure of the serpentine heater track triggers an increase in local resistance. This increased local resistance leads to increased power dissipation, further increasing resistance until breakage occurs, forming a positive feedback loop. A porous layer avoids this effect by allowing current flow to redistribute and preventing increased resistance in one or more regions. Porous heating elements extending above an insulation layer are particularly advantageous.

[0032] Heater assemblies with an insulating layer combined with a porous heating element are particularly advantageous. Such a combination is especially advantageous when the porous heating element extends to cover all heating surfaces of the porous body and, in doing so, covers the insulating layer. In this case, low thermal conductivity into the porous body can be achieved, which reduces heat loss while maintaining consistent heating of the aerosol-forming matrix. In contrast, if a track-type heater, such as a serpentine or electrically parallel track heating element, is combined with an insulating layer, a higher in-plane thermal conductivity of the insulating layer is required to allow heat to diffuse between the heater tracks for uniform heating. However, the lower thermal conductivity of the insulating layer reduces energy loss through the porous body. The porous heating element can extend to only partially cover the heating surface of the porous body. This has the advantage of increasing power density.

[0033] Heater assemblies with insulation and porous heating elements are particularly advantageous because this combination allows heat to be concentrated along the heating elements and allows for the restriction of heat flow and dissipation into the porous body.

[0034] The heating element may include a track. The track may define a path across the heating surface of the insulation layer. The track may define a serpentine path across the heating surface of the insulation layer.

[0035] The heating element may include multiple rails or rail sections arranged such that at least two rails or rail sections are spaced apart by a distance in the range of 150 to 300 micrometers. All rails or rail sections may be spaced apart from at least one other rail section by 150 to 300 micrometers. This has the advantage of providing a particularly efficient heater assembly in which the aerosol-forming matrix is ​​effectively evaporated.

[0036] A heating element may be disposed on at least one surface of the porous body. The heating element may cover at least one surface of the porous body. The heating element may enclose the porous body. The heating element may include resistance rails. When electricity is supplied, the resistance rails can generate heat through the Joule effect. The resistance rails may have any suitable shape, including but not limited to serpentine, meandering, spiral, or multiple parallel rails.

[0037] The heating element may have a depth of up to 250 micrometers. The heating element may have a depth ranging from 0.5 micrometers to 250 micrometers. The heating element may have a depth ranging from 50 micrometers to 250 micrometers. The heating element may have a depth ranging from 5 micrometers to 50 micrometers. The heating element may have a depth ranging from 0.5 micrometers to 10 micrometers. The heating element may have a microstructure indicating that it has been deposited by: foil etching; screen printing; or thin film deposition methods.

[0038] When electricity is supplied, heat loss occurs through the porous body via thermal conduction. Heating elements including tracks are advantageous because heat loss is proportional to the heated area. The tracks can be disposed on the surface or a portion of the porous body. The heating elements can have a surface area less than half, preferably less than one-third, preferably less than one-quarter, and preferably less than one-tenth of the heating surface area of ​​the porous body to increase power density when electricity is supplied. Increasing power density increases the throughput of the liquid to be evaporated, reduces the time to reach boiling, and improves thermal efficiency (by increasing the ratio of power used for evaporation to power lost in the porous body). Power density can be increased by reducing the width of the heater tracks. Power density can also be increased by reducing the gap between the tracks of the heating element. In heater assemblies with insulation, a distance in the range of 150 to 300 micrometers between at least two of a plurality of tracks or track portions is particularly advantageous.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] According to an embodiment of this disclosure, a cylinder is provided. The cylinder may include a heater assembly. The cylinder may include a liquid storage portion for holding an aerosol-forming matrix. The heater assembly may include a heating element for evaporating the liquid aerosol-forming matrix. The heater assembly may include a porous body for conveying the liquid aerosol-forming matrix to the heating element. The heater assembly may include a heat-insulating layer having a lower thermal conductivity than the porous body. The heat-insulating layer may be disposed between the porous body and the heating element. The heat-insulating layer may contact each of the porous body and the heating element. The heat-insulating layer may be configured to reduce heat transfer from the heating element to the porous body. The porous body may include a porous ceramic body or a porous glass body.

[0045] According to an example of this disclosure, a cylinder is provided, the cylinder including a heater assembly and a liquid storage portion for holding a liquid aerosol forming matrix, the heater assembly including: a heating element for evaporating the liquid aerosol forming matrix; a porous body for conveying the liquid aerosol forming matrix to the heating element; and 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.

[0046] The cylinder may include a liquid aerosol forming matrix in the liquid storage section. The liquid aerosol forming matrix may be as described above.

[0047] The porous body can be fluidly connected to the liquid storage section. The porous body may have a liquid-absorbing surface. The liquid-absorbing surface of the porous body can be fluidly connected to the liquid storage section.

[0048] The liquid storage section can be arranged at the liquid absorption surface of the porous body.

[0049] An aerosol generation system is provided. The aerosol generation system may include a cylinder and an aerosol generation apparatus. The cylinder may include a heater assembly. The cylinder may include a liquid storage portion for holding an aerosol-forming matrix. The heater assembly may include a heating element for evaporating the liquid aerosol-forming matrix. The heater assembly may include a porous body for conveying the liquid aerosol-forming matrix to the heating element. The heater assembly may include a heat insulation layer having a lower thermal conductivity than the porous body. The heat insulation layer may be disposed between the porous body and the heating element. The heat insulation layer may contact each of the porous body and the heating element. The heat insulation layer may be configured to reduce heat transfer from the heating element to the porous body. The porous body may include a porous ceramic body or a porous glass body. The aerosol generation apparatus may include a power source for supplying electricity to the heating element. The aerosol generation apparatus may include a control circuit system configured to control the power supply from the power source to the heating element.

[0050] An aerosol generation system is provided, comprising: a cylinder and an aerosol generation apparatus. The cylinder includes a heater assembly and a liquid storage portion for holding a liquid aerosol forming matrix. The heater assembly includes: a heating element for evaporating the liquid aerosol forming matrix; a porous body for conveying the liquid aerosol forming matrix to the heating element; and a heat insulation layer having a lower thermal conductivity than the porous body, wherein the heat insulation layer is disposed between and in contact with the porous body and the heating element, and is configured to reduce heat transfer from the heating element to the porous body. The aerosol generation apparatus may include a power source for supplying power to the heating element; and a control circuit system configured to control the power supply from the power source to the heating element.

[0051] The cylinder may include a liquid aerosol forming matrix in the liquid storage section. The liquid aerosol forming matrix may be as described above.

[0052] Aerosol generation systems can be portable. They can be about the size of a regular cigar or cigarette.

[0053] The cylinder can be removably connected to the aerosol generating device.

[0054] The aerosol forming matrix can be liquid at room temperature. The aerosol forming matrix 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.

[0055] Liquid aerosol forming matrices 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 acid esters; and aliphatic esters of mono-, di-, or polycarboxylic acids such as dimethyl dodecanoate and dimethyl tetradecanoate. Liquid aerosol forming matrices may include water, solvents, ethanol, plant extracts, and natural or artificial fragrances.

[0056] 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%.

[0057] The airflow path can pass through the liquid storage section. For example, the liquid storage section can have an annular cross-section defining an internal passage or aerosol channel, and the airflow path can extend through the internal passage or aerosol channel of the liquid storage section.

[0058] 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. TMThe copolymer is made from three monomers: dimethyl terephthalate (DMT), cyclohexanediol (CHDM), and 2,2,4,4-tetramethyl-1,3-cyclobutanediol (CBDO). The shell can define a liquid storage section or part of a reservoir. The shell can define a liquid storage section. The shell and the liquid storage section can be integrally formed. Alternatively, the liquid storage section can be formed separately from the outer shell and disposed within the outer shell.

[0059] The aerosol generating apparatus may include a power source for supplying electricity to the heater assembly. The aerosol generating apparatus may include a control circuitry system for controlling the power supply from the power source to the heater assembly. The cylinder may be removably coupled to the aerosol generating apparatus.

[0060] 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.

[0061] The housing of the aerosol generating device may define a cavity for a portion of the receiving cylinder. The aerosol generating device may have a connection end configured to connect the aerosol generating device to the cylinder. The connection end may include the cavity for the receiving cylinder.

[0062] 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.

[0063] The control circuitry system may include any suitable controller or electrical component. The controller may include memory. Information used to perform methods of operation of the device or system 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).

[0064] The features described in one of the above examples can also be applied to other examples of this disclosure.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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-forming 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.

[0070] According to an embodiment of this disclosure, a ceramic heating element for an aerosol generation system is provided. The ceramic heating element may include a heating portion for evaporating a liquid aerosol forming matrix. The ceramic heating element may also include a porous portion for conveying the liquid aerosol forming matrix to the heating portion. The heating portion and the porous portion may be integrally formed. A heat insulation layer may be disposed between the heating portion and the porous portion.

[0071] According to an embodiment of this disclosure, a ceramic heating element for an aerosol generation system is provided. The ceramic heating element includes a heating portion for evaporating a liquid aerosol forming matrix. The ceramic heating element also includes a porous portion for conveying the liquid aerosol forming matrix to the heating portion. The heating portion and the porous portion are integrally formed. A heat insulation layer is disposed between the heating portion and the porous portion.

[0072] This example of a ceramic heating element provides an improved component for an aerosol generation system. By providing a ceramic heating element in which a heating portion for evaporating the liquid aerosol forming matrix and a porous portion for conveying the liquid aerosol forming matrix are integrally formed, a more robust and reliable connection can be established between the heating portion and the porous portion. This advantageously helps to improve heat transfer between the heating portion and the porous portion.

[0073] Integrating the heating element integrally with the porous portion 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, provides users of aerosol generation systems with an improved and more pleasant experience. Such an arrangement also helps reduce the likelihood of users experiencing dry heating or dry suction.

[0074] The advantage of integrating the heating element integrally with the porous portion 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 electric heating element relative to the porous portion are also fixed, which helps produce a more consistent aerosol. This is because the electric heating element is fixed to the porous portion, which helps supply the liquid aerosol forming matrix to the heating element. This also helps prevent unwanted heat loss, which helps improve energy efficiency.

[0075] By integrating the heating element integrally with the porous portion, 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 portion 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.

[0076] This type of ceramic heating element may also be advantageous because the risk of the heating part and the porous part becoming separated is greatly reduced.

[0077] Heating elements, insulation layers, and porous bodies can be molded into a single integral part.

[0078] This can help simplify the manufacture of heater components by reducing manufacturing time and providing a more cost-effective solution. It also allows for a tighter mechanical connection between the heating element, insulation layer, and porous body.

[0079] The heating element can be a doped portion of a porous body.

[0080] Porous materials can be doped so that the portion of the porous material that serves as a heating element is conductive. Doping porous materials to provide heating elements 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 of the heating element can range from 5 micrometers to 100 micrometers. The thickness of the doped portion of the heating element 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 for the doped porous material can be an n-type dopant or a p-type dopant. The heating element dopant can be any of, but is not limited to, nitrogen, phosphorus, aluminum, or boron. The interface between the insulating layer and the porous material may include a portion of the partially doped porous material.

[0081] According to an embodiment of 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 ceramic body for conveying the liquid aerosol forming matrix to the heating element. The porous ceramic body may have a liquid absorption surface and a heating surface. The heating element may be located on and bonded to the heating surface of the porous ceramic body. A thermal insulation layer may be disposed between the heating element and the porous ceramic body.

[0082] According to an embodiment of this disclosure, 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 ceramic body for conveying the liquid aerosol forming matrix to the heating element. The porous ceramic body has a liquid absorption surface and a heating surface. The heating element is located on and bonded to the heating surface of the porous ceramic body. A thermal insulation layer is disposed between the heating element and the porous ceramic body.

[0083] The combination of the heating element and the heating surface of the porous ceramic body advantageously provides heater assemblies that are easier and more reliable to manufacture and assemble, thus resulting in more energy-efficient heater assemblies capable of generating more consistent aerosols. This, in turn, provides users of aerosol generation systems with an improved and more pleasant experience. Such an arrangement also helps reduce the likelihood of users experiencing dry heating or dry suction.

[0084] The advantage of placing and integrating the heating element onto the heating surface of the porous ceramic 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 electric heating element relative to the porous body are also fixed, which helps produce a more consistent aerosol. This is because the electric heating element is fixed to the porous ceramic 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.

[0085] By placing and integrating the heating element onto the heating surface of a porous ceramic body, with an insulating layer in between, the resulting aerosol generation system benefits from reduced material requirements. This is because the need for intermediate fixing components that secure 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.

[0086] According to an embodiment of this disclosure, an aerosol generation system is provided. The aerosol generation system may include a heater assembly as described above. The heating element may be fluid-permeable, such that during use, vapor is discharged from the heater assembly in the average vapor discharge direction. The aerosol generation system may further include an air inlet and an aerosol outlet. The air inlet may be in fluid communication with the aerosol outlet to define an airflow path through the aerosol generation system. The heater assembly may be arranged in fluid communication with the airflow path, such that air flows through the heater assembly in the average airflow direction. The heater assembly and the airflow path may be arranged such that the angle between the average vapor discharge direction and the average airflow direction is less than 135 degrees.

[0087] 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.

[0088] The average vapor discharge direction can be substantially perpendicular to the heating surface of the insulation layer. The average vapor discharge direction can also be substantially perpendicular to the heating surface of the porous body. As used herein, the term "substantially perpendicular" means 90 degrees ± 10 degrees, preferably ± 5 degrees.

[0089] The advantage of having the average steam discharge direction substantially perpendicular to the heating surface of the insulation layer 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 insulation layer. 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).

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] The heating element may comprise a porous layer of conductive material. Advantageously, a heating element comprising a porous layer of conductive material allows current to flow through it, enabling resistance heating, and also allows vapor to travel through the heating element via the pores in its porous structure. Therefore, vapor emission occurs through the porous heating element. This avoids the buildup of vapor pressure beneath the heating element and high-speed vapor emission at the sides of the heating element. The inventors have discovered that this arrangement produces a consistent vapor flow across the heating element, and a low vapor emission velocity of approximately 0.1 m / s. Such a low vapor emission velocity means that the vapor is easily carried away by the airflow, thereby reducing the impact of the vapor on the inner walls of the aerosol generation system.

[0097] The porous body may have a liquid-absorbing surface and a heating surface. An insulating layer may be disposed on the heating surface. The liquid-absorbing surface of the porous body may have an area different from that of the heating surface. The porous body may include a porous ceramic body or a porous glass body. The porous body may be substantially incompressible.

[0098] 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.

[0099] 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.

[0100] Improving heating efficiency can reduce the power consumption of heater components during use.

[0101] The heating surface area of ​​a porous body can be smaller than the liquid absorption surface area of ​​the porous body. The heating surface area of ​​an insulation layer can be smaller than the liquid absorption surface area of ​​the porous body. The liquid absorption surface area of ​​a porous body can be larger than the heating surface area of ​​the porous body. The liquid absorption surface area of ​​a porous body can be larger than the heating surface area of ​​the insulation layer.

[0102] 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 can be transferred from the heating element to the porous body and toward the liquid absorption surface via conduction.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] The heating surface of the porous body may be convex in one or both of the first and second transverse directions, with the first transverse direction orthogonal to the second transverse direction. A heat insulation layer may be disposed on the heating surface of the porous body. The heating surface of the heat insulation layer may be convex in one or both of the first and second transverse directions, with the first transverse direction orthogonal to the second transverse direction.

[0110] Including such a porous body or insulating layer allows for an increase in the surface area of ​​the heating surface without increasing the volume of the porous body. This can improve the efficiency of the heater assembly in evaporating liquid aerosols to form a matrix, because it allows for an increase in the surface area of ​​the heating assembly available for evaporating liquid aerosols to form a matrix without increasing the volume of the porous body through which heat loss can occur via conduction.

[0111] Providing a heating surface that protrudes in one or both of the first and second lateral directions allows for an increase in the surface area of ​​the heating surface without increasing its width. This can improve the efficiency of the heater assembly in evaporating liquid aerosols to form a matrix, while helping to avoid the need to redesign other components of the aerosol generation system to accommodate the porous body.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] The heating surface of a porous body or insulation layer can be convex in a single transverse direction.

[0116] The heating surface of the porous body or insulation layer can be convex in both the first and second transverse directions.

[0117] 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 or insulation layer 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.

[0118] The heating element may protrude in one or both of the first and second lateral directions.

[0119] The curvature of the heating element or insulation layer in the first transverse direction can be substantially the same as the curvature of the heating surface of the porous body or insulation layer in the first transverse direction. The curvature of the heating element or insulation layer in the second transverse direction can be substantially the same as the curvature of the heating surface of the porous body or insulation layer in the second transverse direction. The curvature of the heating element or insulation layer in both the first and second transverse directions can be substantially the same as the curvature of the heating surface of the porous body or insulation layer in both the first and second transverse directions, respectively.

[0120] The average pore size of a porous body can vary between the liquid absorption surface and the heating surface of the porous body.

[0121] Porous bodies that provide variations in pore size between the liquid absorption surface and the heating surface of the porous body can 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 absorption surface and the heating surface of the porous body allows the porous body to provide a consistent supply of aerosol forming matrix to the heating surface. This can advantageously avoid undesirable "dry heating." Furthermore, the porous body of the present invention can also advantageously prevent leakage of the liquid aerosol forming matrix from the heating surface of the porous body.

[0122] The average pore size of a porous body can vary in any way between the liquid absorption surface and the heating surface of the porous body. The average pore size can vary from relatively large pores at the liquid absorption surface to relatively small pores at the heating surface of the porous body.

[0123] A porous body having a larger average pore size at the liquid absorption end and a smaller average pore size at the heating end of the porous body particularly facilitates 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 of the porous body 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.

[0124] 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.

[0125] 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 heated surface of the porous body. 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 heated 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 heated surface of the porous body without reducing the flow of the liquid aerosol forming matrix through the porous body.

[0126] The features described in one of the above examples can also be applied to other examples of this disclosure.

[0127] 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.

[0128] Example Ex1. A heater assembly for an aerosol generating apparatus, the heater assembly comprising:

[0129] Heating elements used for evaporating liquid aerosols to form a matrix;

[0130] A porous body for conveying the liquid aerosol forming matrix to the heating element; and

[0131] Compared to the porous body, a heat insulation layer with lower thermal conductivity is provided, wherein the heat insulation layer is disposed between the porous body and the heating element and in contact with 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, wherein the porous body comprises a porous ceramic body or a porous glass body.

[0132] Example Ex2. The heater assembly according to Ex1, wherein the insulation layer comprises an insulation material having a lower thermal conductivity than the porous body.

[0133] Example Ex3. A heater assembly according to Ex1 or Ex2, wherein the insulation layer comprises a material having a thermal conductivity of less than 40 W / m·Kelvin.

[0134] Example Ex4. A heater assembly according to any of the preceding examples, wherein the insulation layer comprises a material having a thermal conductivity of less than 10 W / m·Kelvin.

[0135] Example Ex5. A heater assembly according to any of the preceding examples, wherein the insulation layer comprises an insulation material having a higher porosity than the porous body.

[0136] Example Ex6. A heater assembly according to any of the preceding examples, wherein the insulation layer extends entirely between the porous body and the heating element.

[0137] Example Ex7. A heater assembly according to any of the preceding examples, wherein the heat insulation layer comprises one or more of the following: alumina, zirconium oxide, zirconium oxide having magnesium oxide, glass ceramic, quartz, porous polymer.

[0138] Example Ex8. A heater assembly according to any of the foregoing examples, wherein the insulation layer has a thickness between 0.1 mm and 2 mm, preferably between 0.5 mm and 1.5 mm.

[0139] Example Ex9. A heater assembly according to any of the preceding examples, wherein the heating element is a porous heating element.

[0140] Example Ex10. A heater assembly according to any of the preceding examples, wherein the insulation layer has a heating surface, and the heating element extends to cover a region of the heating surface of the insulation layer.

[0141] Example Ex11. 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 have a distance in the range of 150 to 300 micrometers between them.

[0142] Example Ex12. A heater assembly according to any of the preceding examples, wherein the porous body comprises an electrically insulating material.

[0143] Example Ex13. A heater assembly according to any of the foregoing examples, wherein the heating element and the porous body are integrally formed.

[0144] Example Ex14. A heater assembly according to any of the preceding examples, wherein the insulation layer has a heating surface, and the heating element is located on and coupled to the heating surface of the insulation layer.

[0145] Example Ex15. A heater assembly according to any of the foregoing examples, wherein the porous body has a liquid absorption surface and a heating surface.

[0146] The heating element and the heat insulation layer are located on the heating surface of the porous body.

[0147] The liquid-absorbing surface of the porous body has an area different from that of the heating surface of the porous body.

[0148] Example Ex16. A heater assembly according to Ex15, 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.

[0149] Example Ex17. A heater assembly according to Ex14 or Ex15, wherein the area of ​​the liquid absorption surface of the porous body is smaller than the area of ​​the heating surface of the porous body.

[0150] Example Ex18. A heater assembly according to any of the foregoing examples, wherein the porous ceramic body has a liquid-absorbing surface and a heating surface.

[0151] The heating element and the heat insulation layer are located on the heating surface of the porous ceramic body, and

[0152] The heating surface of the porous body is convex in one or both of a first transverse direction and a second transverse direction, wherein the first transverse direction is orthogonal to the second transverse direction.

[0153] Example Ex19. The heater assembly according to Ex18, wherein the heating surface of the porous body has a radius of curvature of at least about 1.5 mm.

[0154] Example Ex20. A heater assembly according to any of the foregoing examples, wherein the porous body has a liquid absorption surface and a heating surface.

[0155] The heating element is located on the heating surface of the porous body.

[0156] The average pore size of the porous body varies between the liquid absorption surface and the heating surface.

[0157] Example Ex21. A heater assembly according to Example Ex20, wherein the heating element, the insulation layer and the porous body are integrally formed.

[0158] Example Ex22. A heater assembly according to Example Ex20 or Example Ex21, 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.

[0159] 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.

[0160] Example Ex23. A heater assembly according to any of the preceding examples, wherein the heating element comprises a plurality of rails or rail portions arranged in parallel.

[0161] Example Ex24. 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.

[0162] Example Ex25. An aerosol generation system comprising a heater assembly according to any of the preceding examples, wherein the heating element is fluid-permeable such that, in use, vapor is discharged from the heater assembly in the average vapor emission direction;

[0163] 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;

[0164] 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. Attached Figure Description

[0165] The example will now be described further with reference to the accompanying drawings, in which:

[0166] Figure 1 It is a schematic diagram of a cross-section through a heater assembly according to an example of this disclosure, wherein the heating element is a rail heater;

[0167] Figure 2 It is a schematic diagram of a cross-section through a heater assembly according to an example of the present disclosure, wherein the heating element is a porous layer;

[0168] Figure 3 (a) to Figure 3 (c) is a graph showing the effect of increasing thermal conductivity on various factors;

[0169] Figure 4 (a) to Figure 4 (c) is a graph showing the effect of increasing power density on (a) boiling time, (b) throughput and (c) thermal efficiency;

[0170] Figure 5 (a) and Figure 5 (b) is a schematic diagram depicting the current flow through a porous heating element that is defect-free in (a) and defective in (b);

[0171] Figure 6 (a) to Figure 6 (c) is a schematic diagram depicting the heating element track; and

[0172] Figure 7 (a) and Figure 7 (b) is a schematic diagram depicting the current flow around the corner of the heating element track;

[0173] Figure 8 This is a schematic plan view of a heater assembly according to an example of this disclosure;

[0174] Figure 9 yes Figure 8 A schematic cross-sectional view of the heater assembly;

[0175] Figure 10 This is a schematic diagram of the interior of an aerosol generation system according to an example of this disclosure;

[0176] Figure 11This is a schematic cross-sectional view of a portion of an aerosol generation system according to another embodiment of the present disclosure, showing the arrangement of the heater assembly relative to the airflow path within the aerosol generation system;

[0177] Figure 12 This is a schematic cross-sectional view of a portion of another aerosol generation system according to another embodiment of the present disclosure, showing another arrangement of the heater assembly relative to the airflow path within the aerosol generation system;

[0178] Figure 13 This is a schematic diagram of a heater assembly according to an example of this disclosure;

[0179] Figure 14 yes Figure 13 A side view of the schematic diagram;

[0180] Figure 15 This is a schematic diagram of a heater assembly according to an example of this disclosure. Detailed Implementation

[0181] The above and other features and advantages of the exemplary embodiments will become more apparent from the detailed description of the exemplary embodiments with reference to the accompanying drawings. However, the specific structural and functional details disclosed herein are merely representative for the purpose of describing the exemplary embodiments. Furthermore, the exemplary embodiments may be implemented in many alternative forms and should not be construed as being limited to the embodiments set forth herein.

[0182] Therefore, although the exemplary embodiments are capable of various modifications and have alternative forms, embodiments thereof are illustrated by way of example in the accompanying drawings and will be described in detail herein. However, it should be understood that the exemplary embodiments are not intended to be limited to the specific forms disclosed; on the contrary, the exemplary embodiments will encompass all modifications, equivalents, and alternatives that fall within the scope of the exemplary embodiments. Throughout the description of the figures, similar reference numerals indicate similar elements.

[0183] For ease of description, spatially relative terms (e.g., “below”) may be used herein to describe the relationship between one element or feature and another element or feature as shown in the figures. It should be understood that spatially relative terms are intended to cover different orientations of the device during use or operation, other than those depicted in the figures. For example, if the device in the figures is flipped, an element described as “below” other elements or features would be oriented as “above” other elements or features. Therefore, the term “below” can encompass both “above” and “below” orientations. The device may be oriented in other ways (rotated 90 degrees or other orientations), and the spatially relative descriptive terms used herein shall be interpreted accordingly.

[0184] It should be understood that when a component or layer is referred to as being "set on" another component or layer, it may be directly on, connected to, coupled to, or cover the other component or layer, or there may be intermediate components or layers. In contrast, when a component is referred to as being "directly set on" another component or layer, there are no intermediate components or layers.

[0185] The terminology used herein is for the purpose of describing various embodiments only and is not intended to limit the exemplary embodiments. As used herein, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” are intended to include the plural forms as well. It will be further understood that the terms “includes,” “including,” “comprises,” and “comprising”, when used in this specification, specify the presence of the stated features, integrals, steps, operations, or elements, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, or groups thereof.

[0186] Exemplary embodiments are described herein with reference to cross-sectional views, which are schematic diagrams of idealized embodiments (and intermediate structures) of the exemplary embodiments. Therefore, variations in the illustrated shapes, such as due to manufacturing techniques or tolerances, are to be expected. Thus, the exemplary embodiments should not be construed as limited to the shapes of the areas shown herein, but should include, for example, deviations in shape due to manufacturing processes. Therefore, the areas shown in the figures are schematic in nature, and their shapes are not intended to show the actual shapes of areas of the device, nor are they intended to limit the scope of the exemplary embodiments. In all figures, the same reference numerals denote the same elements. Unless explicitly stated otherwise, the figures should not be considered as drawn to scale. It should be understood that the figures in this application are schematic, and some features have been omitted for clarity.

[0187] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which the exemplary embodiments pertain. It will be further understood that terms, including those as defined in commonly used dictionaries, shall be interpreted as having a meaning consistent with their meaning in the context of the relevant field, and shall not be interpreted in an idealized or overly formalized sense unless expressly defined herein.

[0188] The accompanying drawings are intended to depict exemplary embodiments and should not be construed as limiting the intended scope of the claims.

[0189] refer to Figure 1The diagram shows a schematic of a heater assembly 100 for an aerosol generation system according to an example of the present disclosure. The heater assembly 100 includes a heating element 110, a heat insulation layer 120, a porous body 130, and an electrical control circuit system (not shown for clarity).

[0190] The porous body 130 is configured to supply a liquid aerosol forming matrix to the heating element 110. Specifically, the porous body 130 is configured to transfer the liquid aerosol forming matrix from a liquid reservoir (for clarity, in...) Figure 1 (Not shown) is transferred to heating element 110. Porous body 130 is configured to store some liquid aerosol forming matrix before aerosolization by heating element 110.

[0191] The porous body 130 is a rectangular block. The porous body 130 has a first end face and an opposing second end face. The first end face is a liquid-absorbing surface 134, and the second end face is a heating surface 133. In this example, both the liquid-absorbing surface 134 and the heating surface 133 are substantially flat surfaces. The porous body 130 also has a plurality of lateral surfaces extending between the liquid-absorbing surface 134 and the heating surface 133. The porous body 130 has a first lateral surface 131 opposite to a second lateral surface 132 and a third lateral surface (not shown) opposite to a fourth lateral surface (not shown). The porous body 130 has a thickness defined between the liquid-absorbing surface 134 and the heating surface 133.

[0192] The porous body 130 includes a plurality of open pores. The plurality of open pores are interconnected to provide a fluid path for the aerosol-generating liquid to pass through the porous body 130. The heater assembly 100 may be configured such that the liquid can reach the heating element 110 through the fluid path of the porous body 130 as depicted by arrow 170. The porous body 130 is configured to allow fluid 170 to be transferred from the liquid absorption side 134 to the heating surface 133. The porous body 130 contains a material that does not chemically interact with the liquid aerosol matrix. The porous body 130 contains ceramics. The porous body 130 contains porous ceramics, such as, but not limited to, one or more of the following: Al2O3, ZrO2, Si3N4, SiC, Ti3AlC2, BN, AlN, SiO2, MgO, mica, diatomaceous earth, silicates, silicides, borides, and glass. It should be understood that the porous body 130 may have different shapes or contain different materials.

[0193] The heating element 110 is configured to heat the liquid aerosol forming matrix to form an aerosol. The heating element 110 is configured to convert electrical energy into heat energy through the material resistance of the heating element 110 to the current.

[0194] The heating element 110 includes a track defining a path across the heating surface 123 of the insulation layer 120. The heating element 110 defines a serpentine or electrically parallel track shape across the heating surface 123 of the insulation layer 120. Three cross-sections of the portion of the track passing through the heating element 110 are shown in... Figure 1 As shown in the diagram, multiple orbital portions are arranged such that at least two of the multiple orbital portions 118, 119 are spaced apart by a distance ranging from 150 to 300 micrometers. The orbital portions are uniformly spaced. It should be understood that the distances between at least two of the multiple orbital portions 118, 119 may not be equal.

[0195] The heating element 110 is elongated. The heating element 110 comprises a metal, such as, but not limited to, stainless steel, Ni-Cr alloy, NiCrAlY alloy, FeCrAl alloy (e.g., Kanthal), FeCrAlY alloy, Fe3Al alloy, Ni3Al alloy, NiAl alloy, and CuNi alloy. It should be understood that the heating element 110 may have different shapes or contain different materials.

[0196] The heating element 110 is arranged along the outer surface of the insulation layer 120. The heating element 110 is in direct contact with the insulation layer 120.

[0197] The insulation layer 120 is arranged to enhance the insulation between the heating element 110 and the porous body 130. The insulation layer 120 is arranged to extend across at least a portion of the heating element 110 to insulate the heating element 110 from the porous body 130. The insulation layer 120 is configured to reduce heat dissipation through the porous body 130 in order to improve energy efficiency by reducing energy loss.

[0198] The insulation layer 120 is planar. The insulation layer 120 has a size and shape configured to extend across the electric heating element 110. The insulation layer 120 is configured to extend completely across the surface of the heating element 110. The insulation layer 120 is configured to substantially cover the porous body 130 beneath the insulation layer 120.

[0199] The insulation layer 120 has a first end face and an opposing second end face. The first end face is a liquid-absorbing surface 124, and the second end face is a heating surface 123. In this example, both the liquid-absorbing surface 124 and the heating surface 123 are substantially flat surfaces. The liquid-absorbing surface 124 of the insulation layer 120 is in direct contact with the porous body 130. The heating surface 123 of the insulation layer 120 is in direct contact with the heating element 110.

[0200] The insulation layer 120 also has a plurality of lateral surfaces extending between the liquid-absorbing surface 124 and the heating surface 123. The insulation layer 120 has a first lateral surface 121 opposite to the second lateral surface 122 and a third lateral surface (not shown) opposite to the fourth lateral surface (not shown).

[0201] The heat insulation layer 120 is configured such that its first lateral surface 121 extends to the first lateral surface 131 of the porous body 130. The heat insulation layer is configured such that its second lateral surface 122 extends to the second lateral surface 132 of the porous body 130. The heat insulation layer is configured such that its third lateral surface extends to the third lateral surface of the porous body 130. The heat insulation layer is configured such that its fourth lateral surface extends to the fourth lateral surface of the porous body 130.

[0202] The insulation layer 120 has a thickness defined between the liquid-absorbing surface 124 and the heating surface 123. The thickness of the insulation layer 120 is less than the thickness of the porous body 130. The insulation layer may have a thickness between 0.1 mm and 2 mm, preferably between 0.5 mm and 1.5 mm.

[0203] The insulation layer 120 comprises a material with low thermal conductivity. The insulation layer 120 comprises or is composed of a material with even lower thermal conductivity than the porous body 130. The insulation layer 120 may have higher porosity than the porous body 130. The insulation layer 120 may comprise one or more materials such as alumina, zirconium oxide, zirconium oxide with magnesium oxide, glass ceramic, quartz, or porous polymer. It should be understood that the insulation layer 120 may have different shapes or contain different materials.

[0204] refer to Figure 2 A schematic diagram of a heater assembly 100 for an aerosol generation system according to a second embodiment of the present disclosure is shown. The heater assembly 100 includes a heating element 110, a heat insulation layer 120, a porous body 130, and an electrical control circuit system (not shown for clarity).

[0205] Porous body 130 and insulation layer 120 as per... Figure 1 The example shown is described.

[0206] The heating element 110 in the second example is a porous heating element. The heating element 110 extends to cover the area of ​​the heating surface of the insulation layer 120.

[0207] The heating element 110 has a first end face and an opposing second end face. The first end face is a liquid-absorbing surface 114, and the second end face is an outer surface 113. In this example, both the liquid-absorbing surface 114 and the outer surface 113 are substantially flat surfaces. The liquid-absorbing surface 114 of the heating element 110 is in direct contact with the heat insulation layer 120.

[0208] The heating element 110 also has a plurality of lateral surfaces extending between the liquid absorption surface 114 and the outer surface 113. The heating element 110 has a first lateral surface 111 opposite to the second lateral surface 112 and a third lateral surface (not shown) opposite to the fourth lateral surface (not shown).

[0209] The heating element 110 is configured such that its first lateral surface 111 extends to the first lateral surface 121 of the insulation layer 120. The heating element 110 is configured such that its second lateral surface 112 extends to the second lateral surface 112 of the insulation layer 120. The heating element 110 is configured such that its third lateral surface extends to the third lateral surface of the insulation layer 120. The heating element 110 is configured such that its fourth lateral surface extends to the fourth lateral surface of the insulation layer 120.

[0210] In the first and second embodiments, heat loss from the heating element to the porous body and to the liquid within the porous body is reduced. Compared to known devices lacking insulation, the heater assemblies of the first and second embodiments are more efficient because they allow for increased user usage and frequency of use before the device's battery is depleted.

[0211] To further illustrate the problem addressed by the insulation layer, the following simulation illustrates heat loss and dissipation in a known heater assembly without insulation. This type of known heater assembly has a porous body and an electric heating element.

[0212] As a first approximation, it is assumed that heat is dissipated away from the heater in the porous body only by diffusion (i.e., without considering heat diffusion caused by convection due to the movement of the liquid toward the heated surface). In this case, heat will diffuse to a distance d according to equation (1).

[0213]

[0214] Where α M This represents the thermal diffusivity of the porous body and the liquid it contains, and t P It is the duration of suction.

[0215] In α M It is 9.2e-8m 2 / s and t P With a time of 3 seconds, d = 1.1 mm.

[0216] In a second approximation that more closely simulates heat dissipation in practice, the liquid is considered to flow toward the heated surface, restricting the diffusion of heat away from the heated region. In this case, heat conduction in the porous body is the result of a competition between heat diffusion (where heat is transferred from the heated surface to the bulk material of the porous body) and convection (where the liquid flow carries heat back to the heated surface).

[0217] In this approximation, the temperature curve T(z), which asymptotically approaches the steady-state curve and is a function of the distance z from the heated surface, is defined as:

[0218]

[0219] At the heated surface, z = 0, and at a certain distance from the heated surface within the porous body, z < 0, T R It is the temperature of the liquid in the reservoir, and T H ε is the temperature of the heated surface of the heating element. W It is the porosity of the porous body, and u L It is the velocity of the liquid in the porous body toward the heated area.

[0220] When the temperature of the heating element is 250 degrees Celsius, the thermal diffusivity of the porous body is 9.2e-8m. 2 / s, and the liquid flows at a rate of 0.2 ml / min through a 25 mm thick filter with 50% porosity. 2 When the evaporation zone is porous, heat diffuses backward (i.e., away from the heating element into the porous body) α M / (ε W u L = 0.5mm.

[0221] In this approximation, to reduce heat loss in the porous body, the diffusion of heat away from the heated surface must be minimized. This requires one or more of the following:

[0222] High fluid flow rate (u) in porous bodies L ),

[0223] High porosity (ε) in porous materials W ),

[0224] • Low thermal diffusivity (α) M ).

[0225] Thermal diffusivity α M It is the ratio of thermal conductivity k to volumetric heat capacity, expressed by equation (3).

[0226] α M =k / (ρc) p(3)

[0227] Where ρ is the material density, and c p It is the specific heat capacity of the material.

[0228] Thermal diffusivity is reduced by selecting porous materials with high specific heat capacity and low thermal conductivity. Porous materials (such as, but not limited to, cotton, alumina, and zirconium oxide) combine low thermal conductivity with a reasonable specific heat capacity, resulting in a thermal diffusivity of 10 -8 Up to 3×10 -5 m 2 Low thermal diffusivity in the range of / s.

[0229] The inventors have discovered that thermal conductivity is affected by the combination of a porous body and a liquid contained within it. Increasing the thermal conductivity λ of the mixture of porous body and liquid... M This may be detrimental to the proper operation of the evaporation system.

[0230] Simulation results in Figure 3 As shown in the image. Figure 3 This includes showing (a) increasing the thermal conductivity (λ) of porous and liquid mixtures. M (a) The simulated effect on the time to reach boiling, and (b) the increase in the thermal conductivity (λ) of the porous body and liquid combination. M The simulated effect of the energy required for each suction and extraction, and (c) the increase in the thermal conductivity (λ) of the porous body and liquid combination. M A graph showing the simulated effect on thermal efficiency. Regarding its generation... Figure 3 In the model shown in the diagram, the supplied power is adjusted to ensure a constant liquid throughput of 0.2 ml / min through the porous body. When the thermal conductivity of the porous body and liquid combination is increased, more energy diffuses through the porous body and liquid combination. (As shown...) Figure 3 As shown in (a), the time required to reach the boiling point of the liquid increases as the thermal conductivity of the porous body and liquid combination increases. Figure 3 As shown in (b), the energy required for each suction / pump operation increases as the thermal conductivity of the porous body and liquid combination increases. Figure 3 As shown in (c), increasing the thermal conductivity of the porous body and liquid combination has a direct impact on energy efficiency (i.e., the ratio of energy used in the actual evaporation of the liquid to energy wasted in the mixture).

[0231] It was found that for mixtures, the energy efficiency was 67% at a thermal conductivity of 0.225 W / m·Kelvin, while for thermal conductivity above 1 W / m·Kelvin, the energy efficiency dropped to below 50%. The inventors therefore discovered that porous bodies and liquids can be designed to ensure the lowest possible thermal conductivity in order to improve energy efficiency.

[0232] The inventors have also discovered that the power density of the heating element affects its performance. Figure 4 The simulation provides the trend of heated surfaces on a combination of porous materials and liquids, where both the porous material and the liquid have fixed thermal conductivity. For example... Figure 4 As shown in (a), the time required to reach boiling decreases with increasing power density of the heating element. A minimum power density is required to reach boiling during suction, thus defining the threshold Th. The simulation performed defines the minimum power density required to ensure that the liquid boils after 3 seconds (which is the suction duration according to the Coresta scheme). This threshold depends, among other factors, particularly on the surface area of ​​the heated region and the thermal properties of the porous body and the liquid. Figure 4 As shown in (b), extremely low throughput is achieved at the threshold Th. Above the threshold Th, throughput increases approximately linearly with the supplied power density.

[0233] To ensure a usable throughput of 0.2 ml / min (corresponding to a suction rate of 3.3 μl / s or 10 μl / 3 sec), a watt-per-cm² flow rate was simulated. 2 The minimum power density. In this simulation, per 10 watts / cm² 2 The power delivers 7.5 joules per pump, and once the throughput is established, approximately 6 joules of fixed energy are wasted when heating the porous body, while the remainder of the supplied energy is used to evaporate the liquid. Therefore, as... Figure 4 As shown in (c), thermal efficiency increases with power density. Therefore, to maximize thermal efficiency, the evaporation surface area should be kept as small as possible when the heater delivers high power. This increases the liquid flow rate in the porous body, and according to equation (2), the increased liquid flow rate in the porous body reduces heat loss in the porous body (because the higher u...). L This allows T(z) to decrease more quickly. However, this is limited by the properties of the liquid (surface tension, viscosity) and the throughput (porosity) that the porous body can accommodate. If insufficient liquid is supplied to the heating element, the heating element may overheat and eventually break.

[0234] In a model where the 0.5 mm heating side of the porous body is used as a heater with a supply power of 6.25 watts (i.e., body heating), the boiling temperature of 250 degrees Celsius is reached after approximately 1.5 seconds, which is 0.5 to 1.0 seconds later than surface heating (Equation 1). This delay is due to the higher energy required (and wasted) to heat the entire porous body. Although the energy delivered during suction is 19 joules (6.25 watts × 3 seconds), the simulation indicates that 14 joules are needed to heat a 5 × 5 mm porous body. 2 A 1 mm thick slice of porous material is heated to 250 degrees Celsius. This energy is wasted and reduces the thermal efficiency of the evaporation system. Therefore, it is necessary to minimize thermal diffusion of the porous material and reduce energy loss by ensuring that only the surface of the porous material is heated (e.g., by using an insulation layer).

[0235] refer to Figure 5 (a) and Figure 5 (b) shows a schematic diagram of current flow 109 through a porous heating element 110 that is (a) without defects and (b) has defect 108. In this case, the heating element 110 forms a membrane across the insulation layer 120. The porous heating element has, as a... Figure 6 The advantages of the parallel track heating element described in (a) to (c) are as follows.

[0236] Generally, failure of the heater track triggers an increase in local resistance. In the case of a single narrow track design, as seen in existing serpentine systems, this increased local resistance causes more power dissipation, which in turn further increases the resistance until failure occurs, i.e., positive feedback.

[0237] Figure 5 (a) and Figure 5 (b) The heater assembly avoids this effect by allowing current flow to redistribute and avoiding increased resistance in (multiple) regions. Specifically, when a voltage is applied across the heating element, the current flows as... Figure 5 As shown in (a), the current flows in the heating element. Under normal (undamaged) heating conditions, the current flows in parallel within the heating element. As shown in... Figure 5 In the case of heater film damage as shown in defect 108 in (b), the local resistance in the damaged area increases. This increase in local resistance pushes the current away from the damaged area to flow along the path of least resistance, thus avoiding positive feedback that would lead to heater failure. Because heater failure is localized (unlike a single narrow heating track), the overall operation of the heater is maintained, and therefore its lifespan is increased.

[0238] refer to Figure 6 (a) to Figure 6 (c) shows a schematic diagram of the different heating elements 110 used in the aerosol generation system. Each heating element 110 includes multiple rails or rail sections 117 arranged in electrical parallel. Through the electrical parallel arrangement, the current flow is diverted into separate parallel flow paths. The flow paths are then recombined.

[0239] exist Figure 6 (a) to Figure 6In heating elements 110 of (c), each heating element 110 includes a first connecting pad 113 and a second connecting pad 114. The first connecting pad 113 and the second connecting pad 114 are configured to allow connection to an external circuit. An orifice or plurality of orifices 115 in the heating element 110 separates each track 117. Each heating element 110 includes a diverging portion, wherein current is shunt from the first connecting pad 113 into the track 117 defining an electrical parallel path. Each heating element 110 includes a converging portion, wherein current is combined from the track 117 defining the electrical parallel path into the second connecting pad 114.

[0240] Various arrangements of parallel-connected tracks or track sections are possible. Figure 6 In (a), the four tracks 117 are separated by three apertures 115 to define four parallel electrical paths. Figure 6 In (b), the six track sections 117 are separated by an aperture 115 to define two electrically parallel paths. Figure 6 In (b), each electrical parallel path defines a serpentine path between the first connecting pad 113 and the second connecting pad 114. Figure 6 In (c), the eight track sections 117 are separated by four orifices 115 to define four pairs of parallel electrical paths. Figure 6 Each pair of parallel electrical paths in (c) is separated by intermediate connector 116, and the three intermediate connectors are in Figure 6 As shown in (c).

[0241] 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 110; that is, the electrical connection between the first connecting pad 113 and the second connecting pad 114 remains unbroken. This has the advantage of increasing the number of draw-out cycles before the heater completely fails and potentially extending the heater's lifespan to match the lifespan of the device. In contrast, in a simple serpentine heater that defines a single electrical path between the first connecting pad 113 and the second connecting pad 114, if a portion of the serpentine heating element breaks, the heating element will cease to function due to the increased local resistance at the break point or defect point. Defects in a simple serpentine heater cause an increase in local resistance. The increase in local resistance increases power dissipation. Increased power dissipation, in turn, increases resistance until breakage occurs.

[0242] The inventors have also discovered, in reference to Figure 6The parallel rails or rail sections of the electrically parallel arrangement explained in (a) through (c) have a surprising additional advantage. In such an arrangement, even if one rail section breaks, the heating element will still operate advantageously, and can operate advantageously for an initial temporary period, because the breakage of one rail or rail section will result in a higher energy density on the remaining rails or rail sections. In this case, the same power will still be provided, but over a smaller area, thus increasing the throughput. While such a break, which causes an increase in current on the unbroken rails or rail sections, may ultimately degrade the user experience, the device or cylinder may include a mechanism to alert the user that the performance of the heater assembly may be below optimal in the future.

[0243] This mechanism relies on the following principle. The total resistance of the heating element depends on the following factors:

[0244] 1) The number of parallel heating rails (more parallel rails reduce the total resistance);

[0245] 2) The cross-sectional area (width or thickness (or width and thickness)) of the parallel heating rails (a higher cross-sectional area produces lower resistance);

[0246] 3) The length of the parallel heating rails (longer rails have higher resistance);

[0247] 4) If the heating element is porous, adjust the porosity of the heating element (higher porosity increases resistance);

[0248] 5) Specific chemical or material composition (e.g., through doped alloys).

[0249] The overall total heating element resistance R of the arrangement of multiple heating rails or rail sections (i) tot The heating rails or rail sections are arranged in parallel such that the current in at least two adjacent rails or rail sections flows in the same direction, R i This is explained in Equation 4:

[0250]

[0251] Where n is the total number of heating tracks arranged in parallel.

[0252] The behavior of parallel track heating elements when one heating track fails can be referenced for example, Figure 6 Consider the heating element shown in (a) with four parallel heating rails. Each heating rail has a resistance of 3 ohms. Using Equation 4, the total resistance of the heating element is calculated to be 0.75 ohms.

[0253] When a heating rail begins to fail, the resistance of the failed heating rail increases. The total resistance of the heating element also begins to increase, becoming linearly related to the resistance of the failed heating rail. However, as the resistance of the heating rail continues to increase, the resistance of the heating element asymptotically approaches a constant value. At this constant resistance value, the effect of the failed heating rail on the resistance of the heating element is limited. In this example, where each of the unbroken heating rails has a resistance of 3 ohms, the total resistance of the heating element asymptotically approaches 1 ohm when the failed rail can be considered an open circuit (i.e., no current can flow through it). In this example, when one rail breaks, only three rails remain to calculate the total resistance of the heating element.

[0254] To account for this behavior of such a heating element, consider a supply voltage of 3.5 volts and a target power of 5.5 watts. In this example, the unbroken parallel heating rail maintains its initial resistance of 3 ohms. In the failed rail, the total maximum current decreases as resistance increases. In the failed rail, once broken, the current decreases to zero. The current through the unbroken parallel rail remains substantially constant as the resistance of the failed rail increases (if resistance changes due to temperature increases are neglected).

[0255] Similar behavior was observed for maximum heating power generation. Less total power was generated once a heating rail failed. However, in this instance, the maximum power still exceeded the target of 5.5 watts despite the failure of one heating rail.

[0256] and Figure 5 (a) and Figure 5 Compared to the heater film schematically depicted in (b), the increase in overall heating element resistance of the parallel-track heating elements can be monitored by control electronics. In the heater film (such as...) Figure 5 (a) and Figure 5 In (b) of the membrane, the damaged region 108 can widen over time until failure occurs because the current density across the heater membrane (perpendicular to the current flow) increases at the damaged region, generating more power and thus raising the local temperature. This locally increases the resistance of the heater membrane, further increasing the temperature until breakdown (i.e., positive feedback). In contrast, in a parallel-track heating element, the increase in the overall heating element resistance can be monitored by control electronics. The device or system can be configured such that when a predetermined threshold is reached, the device or system informs the user via a user interface that the heater assembly should be replaced.

[0257] The device or cylinder can also be configured to extend the lifespan of the parallel rail heating elements. The aerosol generating device or system may include a control circuitry. The control circuitry can be configured to adjust the power fed to the heater after, for example, a failure of a heating rail is detected via a feedback loop. The control circuitry can be configured to provide a pulse width modulation (“PWM”) signal to control the power fed to the heater. The control circuitry can adjust the power fed to the heater by adjusting the duty cycle of the PWM signal. In an example, the control circuitry can be configured to have a duty cycle of 33.7% when the heating rails are in a normal state. When one of the heating rails has failed, the duty cycle can be increased to 44.9%. When one of the heating rails fails, the power density (heating power generated by the surface area) increases, thereby enhancing the thermal efficiency of the heater body. Therefore, the proper operation of the heater is not compromised by a failed heating rail. A similar result occurs if a second heating rail breaks. The control circuitry can be configured to further increase the duty cycle (reaching 67.4% in the current example). Therefore, even if two of these heating rails break, the heating element with four parallel heating rails can still operate under the nominal condition of 5.5 watts because the duty cycle remains below 100%.

[0258] The control circuitry can be configured such that, once a parallel heating rail has failed, the control circuitry can assess the condition of the heating elements (i.e., the number of failed heating rails) based on the change in the nominal total resistance of the heating elements. The control circuitry can also be configured such that, after a predefined number of heating rails(s) have failed, the device can inform the user that the heater assembly should be replaced.

[0259] Figure 6 (a) to Figure 6 (c) The heating element comprises a plurality of tracks or track portions 117, said plurality of tracks or track portions 117 being arranged such that at least two of the tracks or track portions 117 are spaced apart by distances 118, 119 in the range of 150 to 300 micrometers. This has the advantage of providing particularly effective heating of the matrix at the heating element 110 while limiting heat loss through the porous body 130.

[0260] refer to Figure 7 (a) and Figure 7 (b) shows a schematic diagram of the current flow 109 around the corner of the heating element track.

[0261] Figure 7(a) is a schematic diagram of current flow 109 around a known heating element, 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 109 following the path of least resistance, is concentrated (i.e., the current density increases). This concentration occurs at the inner edges of the corners. This concentration can increase the 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. Although the local resistivity of the heater track material may increase due to the increase in local temperature (which directs the current flow to a path of lower resistance), hot spots still occur.

[0262] Figure 7 (b) is a schematic diagram of the current flow 109 around the heating element, wherein the track portion 117 defines a path with a bend, the inner edge of which is curved. In such a track 117, the current flow 109 does not form local hot spots.

[0263] and Figure 7 Compared to the orbital shape shown in (a), as Figure 7 (b) shows that the current flow 109 in the smoother curved track section 117 is more evenly distributed across the heating track 117, as depicted by the dashed arrow 109. The current flow 109 is guided to flow more evenly to avoid current concentration at any point. This, in turn, limits hot spot formation. The heater track 117 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.

[0264] refer to Figure 8 The image shows a heater assembly 200, which includes a heating element 204 for evaporating a liquid aerosol forming matrix and a porous body 202 for supplying the liquid aerosol forming matrix from a reservoir or liquid storage section (not shown) to the heating element. The porous body 202 has a liquid absorption surface (not shown) and a heating surface 202a. The heating element 204 is arranged on the heating surface 202a of the porous body 202.

[0265] The heating element 204 is formed of a layer of conductive material, allowing current to pass through it to heat it via resistance heating or Joule heating. The heating element 204 is also porous, making it fluid-permeable, and vapor can pass through the heating surface 202a of the porous body 202. Therefore, in Figure 8In the heater assembly 200, vapor emission occurs via a heating element 204. The heating element 204 may comprise a thin metal layer or film having pores extending through its thickness. Alternatively, the heating element may comprise a metal foam having interconnected open pores extending through its thickness. In this example, the porous body 202 comprises a porous ceramic body formed of a suitable ceramic material, such as Al2O3. Furthermore, the heating element 204 has been deposited on the porous ceramic body 202 using a suitable physical or chemical vapor deposition process.

[0266] The heater assembly 200 also includes electrical contacts 206 electrically connected to the heating element. The electrical contacts 206 are arranged on and near the opposite ends of the heating surface 202a. The electrical contacts 206 are disposed over an insulating layer between the heating surface 202a and the heating element 204. The heating element 204 extends between the electrical contacts 206. The electrical contacts 206 are arranged to connect to a control circuitry system for controlling the power supply to the heating element. The electrical contacts 206 are formed of a material with higher conductivity than heating elements such as copper, gold, or zinc, but other suitable materials can be used. This avoids the generation of excessive, wasted heat in the electrical contacts.

[0267] Figure 9 It shows Figure 8 A schematic cross-sectional view of the heater assembly 200. Features are not drawn to scale for clarity and simplicity. Liquid absorption surface 202b is shown. Figure 9 The lower surface of the porous body 202 is shown in the diagram, and the heating surface 202a is also shown as the lower surface of the porous body 202. However, it should be understood that the orientation of these surfaces may differ during use or once the heater assembly 200 is installed in the aerosol generating device. Liquid stored in a liquid reservoir or liquid storage section (not shown) contacts the liquid absorption surface 202b, and as... Figure 9 As indicated by arrow E, the liquid aerosol forming matrix is ​​conveyed through the porous body 202 to the heating surface 202a. A porous heating element 204 is arranged on the heating surface 202a of the porous body 202 and heats the liquid aerosol forming matrix conveyed thereto, causing the liquid aerosol forming matrix to boil and generate vapor. The porous heating element 204 has multiple pores extending from the heating surface 202a through the thickness of the heating element to the exterior of the heater assembly 200.

[0268] Because the heating element 204 is porous, the vapor generated during heating of the heating element 204 can pass through the pores of the heating element 204, and as... Figure 9As indicated by arrow F, vapor is emitted from heating surface 202a. The heating element does not have any impermeable sections that prevent vapor release and cause vapor pressure buildup below the heating element. This reduces the rate at which vapor is emitted from heating element 204 compared to conventional impermeable track heating elements. Simulations have shown that the average vapor emission velocity from heating surface 202a is 0.1 m / s at a power of 6.3 watts. Such a low vapor emission velocity means that vapor can be easily carried away by the airflow in the airflow path without impacting the inner walls of the airflow path and causing condensation. As indicated by arrow F, the average vapor emission direction is substantially perpendicular to the heating surface 202a of the porous body 202, and the vapor is emitted uniformly across the surface of the heating element.

[0269] Figure 10 This is a schematic diagram of the interior of an aerosol generating system 800 according to an embodiment of the present disclosure. The aerosol generating system 800 includes two main components: a cartridge 801 and a main body or aerosol generating device 900. The cartridge 801 is removably connected to the aerosol generating device 900. The aerosol generating device 900 includes a device housing 901 that houses a power source (in this example, a rechargeable lithium-ion battery) in the form of a battery 902 and a control circuitry system 903. The aerosol generating system 800 is portable and has a size comparable to a conventional cigar or cigarette. A mouthpiece is disposed at the opening end of the cartridge 801.

[0270] Cylinder 801 includes a housing that houses heater assembly 100 and a liquid reservoir or liquid storage section 803 for holding the liquid aerosol forming matrix. The liquid aerosol forming matrix is ​​conveyed downward from liquid absorption surface 134 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 heating surface 133.

[0271] Cylinder 801 includes one or more air inlets 804 formed in a cylinder housing 805 at locations along the length of cylinder 801. An aerosol outlet 806 is located in a mouthpiece at the opening end of cylinder 801. The one or more air inlets 804 are in fluid communication with the aerosol outlet 806 to define an airflow path through cylinder 801 of the aerosol generation system 800. The airflow path flows from the one or more air inlets 804 to heater assembly 100 in an airflow passage. Heater assembly 100 is arranged in fluid communication with the airflow path in the airflow passage. Air enters the one or more air inlets 804 and flows through the airflow passage into heater assembly 100 in the average airflow direction.

[0272] exist Figure 10In this example, the liquid storage section 803 has an annular cross-section and is arranged around a centrally sealed aerosol channel 807. 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 807 to the aerosol outlet 806.

[0273] The aerosol generation system 800 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 806. In operation, when the user inhales onto the mouthpiece, air is drawn in through one or more air inlets 804, along an airflow path through an airflow channel, past and around the heater assembly 100, and along an airflow path through an aerosol channel 807 to the aerosol outlet 806. When the system is activated, a control circuit system 903 controls the power supply from the battery 902 to the cartridge 801. This, in turn, controls the amount and nature of the vapor produced by the heater assembly 100. The control circuit system 903 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 801, 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 aerosol outlet 806.

[0274] Figure 11 This is a schematic cross-sectional view of a portion of an aerosol generation system 300 according to another embodiment of the present disclosure, showing the arrangement of the heater assembly 300 relative to the airflow path 320 within the aerosol generation system 300. For simplicity, [the image is] from [the original text]. Figure 11 Other components of the aerosol generation system are omitted. Figure 11 heater assembly 200 and Figure 8 and Figure 9 The heater assembly 200 is identical to that of the aerosol generation system 300. The aerosol generation system 300 includes a liquid storage section 322 that holds a liquid aerosol forming matrix in contact with the liquid absorption surface 202b of the porous body 202. As indicated by arrow E, the liquid aerosol forming matrix is ​​transported from the liquid storage section 322 through the porous body 202 to the heating surface 202a. Evaporated aerosol forming matrix is ​​discharged from the heating surface 202a through the porous heating element 204. As indicated by arrow F, the average vapor discharge direction is substantially perpendicular to the heating surface 202a of the porous body 202.

[0275] exist Figure 11In one example, the heater assembly 200 is arranged below or to one side of an airflow channel or path 320, which is defined by an airflow channel wall 324. For example... Figure 11 As observed, the left end of the visible portion of the airflow path 320 receives airflow from an air inlet (not shown), and the right end of the visible portion of the airflow path delivers airflow to an aerosol outlet (not shown). The heating surface 202a of the porous body 202 is arranged parallel to and facing the airflow path 320. The heater assembly 200 is in fluid communication with the airflow path, such that the airflow in the airflow path flows through the heater assembly 200 in the average airflow direction as indicated by arrow G. The heater assembly 200 and the airflow path 320 are arranged such that the angle θ between the average vapor discharge direction F and the average airflow direction G is approximately 90 degrees (that is, substantially perpendicular to the average airflow direction G at an angle θ). The average vapor discharge direction F has no velocity or directional component relative to the average airflow direction G, and thus reduces any momentum loss of the airflow. This reduces the tendency for recirculation and turbulence to occur in the airflow path 320, and the vapor is less likely to impinge on the inner surface of the airflow passage wall 324.

[0276] Figure 12 This is a schematic cross-sectional view of a portion of an aerosol generation system 400 according to another embodiment of the present disclosure, showing another arrangement of the heater assembly 200 relative to the airflow path 420 within the aerosol generation system 400. For simplicity, [the image is] from [the original text]. Figure 12 Other components of the aerosol generation system are omitted. Figure 12 heater assembly 200 and Figure 8 and Figure 9 The heater assembly 200 is identical to that of the aerosol generation system 400. The aerosol generation system 400 includes a liquid storage section 422 that holds a liquid aerosol forming matrix in contact with the liquid absorption surface 202b of the porous body 202. As indicated by arrow E, the liquid aerosol forming matrix is ​​transported from the liquid storage section 422 through the porous body 202 to the heating surface 202a. Evaporated aerosol forming matrix is ​​discharged from the heating surface 202a through the porous heating element 204. As indicated by arrow F, the average vapor discharge direction is substantially perpendicular to the heating surface 202a of the porous body 202.

[0277] exist Figure 12In this example, the airflow channel or path 420 is divided into a first airflow path segment 420a and a second airflow path segment 420b passing through either side of the heater assembly 200. The first airflow path segment 420a and the second airflow path segment 420b combine downstream of the heater assembly 200 to form a third airflow path segment 420c. The first airflow path segment 420a and the second airflow path segment 420b receive airflow from one or more air inlets (not shown), and the third airflow path segment 420c delivers the airflow to an aerosol outlet (not shown). The airflow path 420 is defined by an airflow channel wall 424. The heating surface 202a of the porous body 202 is arranged substantially perpendicular to the airflow path 420 and faces downstream of the airflow path 420. The heater assembly 200 is in fluid communication with the airflow path such that the airflow in the airflow path flows through the heater assembly 200 in the average airflow direction as indicated by arrow G.

[0278] The heater assembly 200 and the airflow path 220 are arranged such that the angle θ between the average vapor discharge direction F and the average airflow direction G is less than 90 degrees. Upstream of the heating surface 202a of the porous body 202, the average airflow direction G through the heater assembly 200 is substantially the same as the vapor discharge direction F. At a point along the airflow path 420 corresponding to the heating surface 202a, the airflow path 420 begins to narrow or taper inward, at which point the average airflow direction G through the heater assembly 200 changes to an angle θ of approximately 45 degrees relative to the vapor discharge direction F. In the third airflow path segment 420c, downstream of the heating surface 202a of the porous body 202, the average airflow direction G of the combined airflow is again substantially the same as the vapor discharge direction F. It should be understood that the narrowing or tapering of the airflow path 420 can be omitted. In this case, the average airflow direction G through the heater assembly 100 will be substantially the same as the vapor discharge direction F.

[0279] Figure 13 and Figure 14 A schematic diagram of an example of a heater assembly 500 for an aerosol generation system is shown. The heater assembly includes a heating element 510 and a porous body 520.

[0280] The heating element 510 is configured to evaporate an aerosol-forming matrix (such as a liquid aerosol-forming matrix) to form an aerosol. The heating element 510 is configured to convert electrical energy into heat energy through the material resistance of the heating element 510 to the current.

[0281] The porous body 520 is configured to deliver a liquid aerosol forming matrix to the heating element 510. In other words, the porous body 520 supplies the liquid aerosol forming matrix to the heating element 510.

[0282] The porous body 520 has a first end face and an opposing second end face. The first end face is a liquid-absorbing surface 530, and the second end face is a heating surface 540. In this example, both the liquid-absorbing surface 530 and the heating surface 540 are substantially flat surfaces. The porous body 520 also has a plurality of lateral surfaces extending between the liquid-absorbing surface 530 and the heating surface 540.

[0283] In this example, as will be discussed in more detail below, the porous body 520 has a first lateral surface 550 opposite to the second lateral surface 560 and a third lateral surface 570 opposite to the fourth lateral surface 580.

[0284] The porous body 520 includes a plurality of pores. These pores are interconnected to provide a fluid path for the liquid aerosol forming matrix to pass through the porous body 520, from the liquid absorption surface 530 to the heating surface 140. The porous body 520 is formed of a material that does not chemically interact with the liquid aerosol forming matrix. In this example, the porous body 520 is a porous ceramic body and may be formed, for example, from Ca2SiO3 or SiO2 (or Ca2SiO3 and SiO2). In another example, the porous body 520 may be, for example, a porous glass.

[0285] The heating element 510 is located on the heat insulation layer 590 on the porous body 520. Figure 13 and Figure 14 In one example, the heating element 510 is a porous membrane extending across virtually all of the heating surfaces 540.

[0286] The liquid absorption surface 530 of the porous body 520 has an area different from the heating surface 540 of the porous body 520. Specifically, in Figure 13 and Figure 14 In this example, the area of ​​the heating surface 540 is smaller than the area of ​​the liquid absorption surface 530.

[0287] exist Figure 13 and Figure 14 In one example, the heating surface 540 has a smaller area than the liquid absorbing surface 530 because the length of the heating surface 540 is less than the length of the liquid absorbing surface 530. Alternatively, in another example, the heating surface 540 may have a smaller area than the liquid absorbing surface 530 because the width of the heating surface 540 is less than the width of the liquid absorbing surface 530.

[0288] exist Figure 13 and Figure 14In one example, the porous body 520 is formed as a trapezoidal prism. When the porous body 520 has a trapezoidal prism shape, both the first lateral surface 550 and the second lateral surface 560 have trapezoidal shapes, particularly isosceles trapezoids; both the third lateral surface 570 and the fourth lateral surface 580 have rectangular shapes; and both the liquid-absorbing surface 530 and the heating surface 540 have rectangular shapes. In another example, the liquid-absorbing surface 530 and the heating surface 540 may have square shapes.

[0289] The porous body 520 tapers from the liquid absorption surface 530 toward the heating surface 540. In other words, the cross-sectional area of ​​the porous body 520 gradually decreases from the liquid absorption surface 530 toward the heating surface 540. Figure 13 and Figure 14 In this example, the length of the porous body 520 decreases from the liquid absorption surface 530 toward the heating surface 540, which causes a taper.

[0290] The heater assembly 500 includes an insulation layer 590.

[0291] The heating element 510 is arranged along the heating surface of the insulation layer 590. The heating element 510 is in direct contact with the insulation layer 590.

[0292] The insulation layer 590 is arranged to enhance the insulation between the heating element 510 and the porous ceramic body 520. The insulation layer 590 is arranged to extend across at least a portion of the heating element 510 to insulate the heating element 510 from the porous ceramic body 520. The insulation layer 590 is configured to reduce heat dissipation through the porous ceramic body 520 in order to improve energy efficiency by reducing energy loss.

[0293] Figure 15 A heater assembly 600 for use in an aerosol generation system is shown. The heater assembly 600 includes a heating element 610 for evaporating a liquid aerosol forming matrix. The heater assembly 600 also includes a porous ceramic body 620 for conveying the liquid aerosol forming matrix to the heating element 610. The porous ceramic body 620 has a liquid-absorbing surface 621 and an opposing heating surface 622. The heating element 610 is located on an insulating layer 630. The insulating layer 630 is located on the heating surface 622 of the porous ceramic body 620.

[0294] The heating surface 622 of the porous ceramic body 620 is curved. In particular, the heating surface 622 of the porous ceramic body 620 is curved in a convex manner in a single transverse direction (first transverse direction).

[0295] The porous body 620 is prismatic in shape. When observing a longitudinal section perpendicular to the curvature direction of the porous body 620, the heating surface 622 of the porous body 620 appears as an arc. The porous body 620 has two longitudinally symmetrical planes.

[0296] The heating surface 620 of the porous ceramic body 620 has a width 623 in the first transverse direction, which is substantially the same as the width of the porous ceramic body 620 in the first transverse direction, and substantially the same as the width of the heater assembly 600 in the first transverse direction. The heating surface 620 of the porous ceramic body 620 has a width of about 5 mm in the first transverse direction.

[0297] The heating surface 620 of the porous ceramic body 620 has a length or thickness of about 1 mm. The porous ceramic body 620 has a length or thickness of about 3 mm.

[0298] The heating surface 620 of the porous ceramic body has a radius of curvature of approximately 3.6 mm. The heating surface 620 of the porous ceramic body has a surface area of ​​approximately 28 square millimeters.

[0299] The porous body 620 includes four longitudinal surfaces or sidewalls extending from the liquid absorption surface 621 to the heating surface 622. The four sidewalls are substantially perpendicular to the substantially flat liquid absorption surface 621. The liquid absorption surface 621 is square in shape.

[0300] The heating element 610 is a resistance heating element 610.

[0301] The heating element 610 is curved. In particular, the curvature of the heating element is substantially the same as the curvature of the heating surface 622 of the porous ceramic body 120. Thus, the heating element 610 is also curved in a convex manner in a single lateral direction.

[0302] The heating element 610 is located directly on the heating surface 622 of the porous ceramic body 620. The heating element 610 extends across most of the heating surface 622 of the porous ceramic body 620. The heating element 610 is substantially entirely in contact with the heating surface 622 of the porous ceramic body 620.

[0303] The heater assembly 600 includes a heat insulation layer 630 located between a porous ceramic body 620 and a heating element 610. The heat insulation layer 630 is in direct contact with both the heating surface 622 of the porous ceramic body 620 and the heating element 610. The heat insulation layer 620 substantially covers the entire heating surface 622 of the porous ceramic body 620.

[0304] The insulation layer 630 is arranged to enhance the insulation between the heating element 610 and the porous ceramic body 620. The insulation layer 630 is configured to reduce heat dissipation through the porous ceramic body 620, thereby improving the energy efficiency of the heater assembly 600 by reducing energy loss.

[0305] The heat insulation layer 630 is curved. In particular, the heat insulation layer 630 is curved in a convex manner in a single lateral direction (first lateral direction). The curvature of the heat insulation layer 630 corresponds to the curvature of the heating surface 622 of the porous ceramic body 620.

[0306] Specifically, the heat insulation layer 620 has a first end face and an opposing second end face. The first end face is a liquid-absorbing surface 631, and the second end face is a heating surface 632. Both the liquid-absorbing surface 631 and the heating surface 632 of the heat insulation layer 630 are convexly curved in a first transverse direction, and their curvature corresponds to the curvature of the heating surface 622 of the porous ceramic body 620.

[0307] For the purposes of this specification and the appended claims, unless otherwise indicated, all figures representing quantities, quantities, percentages, etc., shall be understood to be modified by the term "about" in all cases. Furthermore, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein, which may or may not be specifically listed herein. Thus, in this context, the number A is understood to be A ± 10 percent (10%) of A. In this context, the number A can be considered as a value within the general standard error for the measurement of the attribute modified by the number A. In some cases used in the appended claims, the number A may deviate from the percentages listed above, provided that the amount of deviation from A does not materially affect the essential and novel features of the claimed invention. Furthermore, all ranges include the disclosed maximum and minimum points, and include any intermediate ranges therein, which may or may not be specifically listed herein.

Claims

1. A heater assembly for an aerosol generating apparatus, the heater assembly comprising: Heating elements used for evaporating liquid aerosols to form a matrix; A porous body used to transport the liquid aerosol forming matrix to the heating element; as well as Compared to the porous body, a heat insulation layer with lower thermal conductivity is provided, 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. The porous body includes a porous ceramic body or a porous glass body; and The heating element forms a membrane across the insulation layer.

2. The heater assembly of claim 1, wherein the insulation layer comprises an insulation material having a lower thermal conductivity than the porous body.

3. The heater assembly according to claim 1 or claim 2, wherein the insulation layer comprises a material having a thermal conductivity of less than 40 W / m·Kelvin.

4. The heater assembly according to any one of the preceding claims, wherein the insulation layer comprises a material having a thermal conductivity of less than 10 W / m·Kelvin.

5. The heater assembly according to any one of the preceding claims, wherein the insulation layer comprises an insulation material having higher porosity than the porous body.

6. The heater assembly according to any one of the preceding claims, wherein the heat insulation layer extends completely between the porous body and the heating element.

7. The heater assembly according to any one of the preceding claims, wherein the heat insulation layer comprises one or more of the following: alumina, zirconium oxide, zirconium oxide having magnesium oxide, glass ceramic, quartz, porous polymer.

8. The heater assembly according to any one of the preceding claims, wherein the heat insulation layer has a thickness between 0.1 mm and 2 mm, preferably between 0.5 mm and 1.5 mm.

9. The heater assembly according to any one of the preceding claims, wherein the heating element is a porous heating element.

10. The heater assembly according to any one of the preceding claims, wherein the insulation layer has a heating surface, and the heating element extends to cover a region of the heating surface of the insulation layer.

11. The heater assembly according to any one of the preceding claims, 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 have a distance in the range of 150 to 300 micrometers between them.

12. The heater assembly according to any one of the preceding claims, wherein the porous body comprises an electrically insulating material.

13. The heater assembly according to any one of the preceding claims, wherein the heating element and the porous body are integrally formed.

14. The heater assembly according to any one of the preceding claims, wherein the insulation layer has a heating surface, and the heating element is located on and coupled to the heating surface of the insulation layer.

15. An aerosol generation system comprising a heater assembly according to any one of the preceding claims, wherein the heating element is fluid-permeable such that, in use, vapor is discharged from the heater assembly in an average vapor emission direction; 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.

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