Aerosol generator with an insulating heater

Abstract

The present invention relates to a heater assembly for an aerosol generating device. The heating assembly comprises a heating chamber for heating an aerosol forming substrate. The heater assembly further comprises a heater casing. The heater casing is arranged around the heating chamber. The heater casing is further arranged radially spaced from the heating chamber. The heater assembly further comprises a first connecting wall and a second connecting wall. The heater assembly further comprises an airtight hollow space. The airtight hollow space is defined between the heating chamber, the heater casing, and the first and second connecting walls. The present invention also relates to an aerosol generating device comprising a heater assembly, and an aerosol generating system comprising an aerosol generating device and an aerosol forming substrate.

Description

Technology Field

[0001] The present disclosure relates to a heater assembly for an aerosol generating device. The present disclosure further relates to an aerosol generating device. The present disclosure also relates to an aerosol generating system comprising an aerosol generating device and an aerosol generating substrate. Background Technology

[0002] It is known to provide an aerosol generating device for generating inhalable vapor. Such a device can heat an aerosol-forming material contained in an aerosol generating article without burning the aerosol-forming material. The aerosol generating article may have a rod shape for inserting the aerosol-forming article into the heating chamber of the aerosol generating device. When the aerosol-forming article is inserted into the heating chamber of the aerosol generating device, a heating element is generally arranged in or around the heating chamber to heat the aerosol-forming material.

[0003] Heat generated by the heating element may be unintentionally released from the heating chamber. Heat may be dissipated into the environment or other components of the aerosol generation system. Heat may be unintentionally dissipated from the heating chamber through free air convection. Heat may be unintentionally dissipated from the heating chamber by heat conduction through components of the aerosol generation device. Heat may be unintentionally dissipated from the heating chamber by heat conduction through components of the aerosol generation article, for example, through the aerosol forming substrate. Heat dissipation from the heating chamber may cause heating of device components that are not intended to be heated. For example, the housing of the device to be held by a user may become uncomfortably hot. Heat dissipation away from the heating chamber may cause heat loss within the heating chamber. Heat loss within the heating chamber may result in less efficient heating. Excess energy may be required to heat the heating chamber to the desired temperature.

[0004] It would be desirable to have an aerosol generator capable of reducing heat loss from the heating chamber. It would be desirable to insulate the heating chamber with respect to other components of the aerosol generator. It would be desirable to have an aerosol generator capable of reducing heating of the outer housing of the device to be held by the user. It would be desirable to have an aerosol generator capable of providing effective insulation. It would be desirable to have an aerosol generator capable of providing insulation at a low manufacturing cost. It would be desirable to have an aerosol generator capable of providing lightweight insulation.

[0005] According to an embodiment of the present invention, a heating assembly for an aerosol generating device is provided. The heating assembly may include a heating chamber for heating an aerosol forming substrate. The heater assembly may include a heater casing. The heater casing may be arranged around the heating chamber. The heater casing may be arranged radially spaced from the heating chamber. The heater assembly may include a first connecting wall. The heater assembly may further include a second connecting wall. The heater assembly may include an airtight hollow space. The airtight hollow space may be defined between the heating chamber, the heater casing, and the first and second connecting walls.

[0006] According to an embodiment of the present invention, a heating assembly for an aerosol generating device is provided. The heating assembly comprises a heating chamber for heating an aerosol forming substrate. The heater assembly further comprises a heater casing. The heater casing is arranged around the heating chamber. The heater casing is further arranged radially spaced from the heating chamber. The heater assembly further comprises a first connecting wall and a second connecting wall. The heater assembly further comprises an airtight hollow space. The airtight hollow space is defined between the heating chamber, the heater casing, and the first and second connecting walls.

[0007] Advantageously, heat loss due to air circulation between the inside and outside air of the heater casing can be reduced or avoided, for example, by providing an airtight hollow space around the heating chamber, at least partially. Providing an airtight hollow space around the heating chamber can also help reduce or avoid heat loss due to air convection within the airtight hollow space. Advantageously, by providing an airtight hollow space around the heating chamber, insulation of the heating chamber against the outer surface of the heater casing can be provided. A heater assembly for an aerosol generator is provided that can reduce heat loss from the heating chamber by providing an airtight hollow space around the heating chamber. A heater assembly for an aerosol generator is provided that can reduce heating of the outer housing of the device to be held by the user by providing an airtight hollow space around the heating chamber. A heater assembly for an aerosol generator is provided that can provide effective insulation by providing an airtight hollow space around the heating chamber. A heater assembly for an aerosol generator is provided that can provide insulation at a low manufacturing cost by providing an airtight hollow space around the heating chamber. A heater assembly for an aerosol generator is provided, which can provide lightweight thermal insulation by providing an airtight hollow space around a heating chamber.

[0008] As used herein, the terms “upstream,” “forward,” and “downstream,” and “rear” are used to describe the relative positions of components of an aerosol generator, or parts of components, with respect to the direction in which air flows through the aerosol generator during use. An aerosol generator according to the present invention includes a proximal end through which aerosol exits the device during use. The proximal end of the aerosol generator may also be referred to as a mouse end or a downstream end. The mouse end is downstream of the distal end. The distal end of the aerosol generating article may be referred to as an upstream end. Components of the aerosol generator or parts of components may be described as being upstream or downstream of each other based on their relative positions with respect to the airflow path of the aerosol generator.

[0009] The proximal end of the heater assembly according to the present invention is configured to be arranged within the aerosol generating device in a direction toward the mouse end or downstream end of the device. The distal end of the heater assembly according to the present invention is configured to be arranged within the aerosol generating device in a direction toward the distal end or upstream end of the device. The longitudinal axis of the heating chamber may extend between the proximal end of the heating chamber and the distal end of the heating chamber. The longitudinal axis of the heating chamber may extend between the proximal end of the heater assembly and the distal end of the heater assembly.

[0010] The heater casing is arranged radially spaced from the heating chamber at a distance (d). The distance (d) can be measured in a direction perpendicular to the longitudinal axis of the heating chamber. The heating chamber may include a heating chamber wall. The heater casing may include a wall of the heater casing. The distance (d) can be measured radially between the wall of the heating chamber and the wall of the heater casing. The distance (d) can be measured radially between the outer side of the wall of the heating chamber and the inner side of the wall of the heater casing.

[0011] The distance (d) between the heating chamber and the heater casing may be 2.5 millimeters to 7 millimeters. The distance (d) between the heating chamber and the heater casing may be 3.5 millimeters to 6 millimeters, preferably about 4.6 millimeters.

[0012] When the distance (d) described above is provided, the air or other gas composition enclosed within the airtight hollow space can be considered as still air. Still air, or non-moving air, further reduces air convection within the airtight hollow space. Accordingly, heat loss due to air convection within the airtight hollow space can be further reduced. Insulation can be further improved. The distance (d) described above has been found to sufficiently reduce heat loss. Furthermore, the distance (d) described above has been found to be particularly effective with the gas composition used in the airtight hollow space, as described in more detail below. Preferably, using ambient air in the airtight hollow space with the distance (d) described above results in cost-effective and efficient insulation.

[0013] Each of the first and second connecting walls may extend between the wall of the heating chamber and the wall of the heater casing. The first and second connecting walls may seal the heater casing to the outer wall of the heating chamber. The connecting walls may be oriented perpendicular to the longitudinal axis of the heating chamber. The first connecting wall may be a proximal connecting wall. The second connecting wall may be a distal connecting wall.

[0014] As used herein, the term “hollow space” refers to a volume substantially devoid of solid material, that is, not filled with a solid compound or substance. In other words, the term “hollow space” refers to a volume that may be filled with a gaseous composition but otherwise remains empty. The hermetic hollow space is hermetically sealed from the outside air. That is, the interior of the hermetic hollow space is not fluidly connected to the outside air. Accordingly, heat loss due to gas circulation between the hermetic hollow space and the outside air of the heater assembly can be avoided.

[0015] Known insulating materials with good thermal insulation properties often require solid materials such as aerogel. Known insulating materials can be complex to manufacture. Known insulating materials can be expensive to produce. A heater assembly containing a hermetic hollow space may be less complex to manufacture compared to a heater assembly that requires additional solid material to be arranged around the heating chamber. The hermetic hollow space may be cheaper compared to solid materials, such as aerogel. The hermetic hollow space may have lower thermal conductivity compared to solid materials. Consequently, better insulation can be provided. The hermetic hollow space may have lower mass compared to solid materials. Consequently, lighter insulating materials can be provided.

[0016] The hermetic hollow space may be filled with a gaseous composition. The hermetic hollow space may be filled with a gaseous composition at approximately ambient pressure. The gas pressure within the hermetic hollow space may be 0.9 atm to 1.1 atm, preferably about 1.0 atm. The hermetic hollow space may be filled with a gaseous composition at approximately ambient pressure at about 20°C. As is known to those skilled in the art, a temperature-dependent change in the gas pressure within the hermetic hollow space may occur.

[0017] The gas composition may include an inert gas. The gas composition may include one or more of nitrogen and argon. The gas composition may have the composition of ambient air. The gas composition may include about 80% nitrogen and about 20% oxygen. The hermetic hollow space may be filled with ambient air.

[0018] The gas composition may have the composition of ambient air at ambient pressure. A gas composition having the composition of ambient air at ambient pressure offers the advantage that a heater assembly containing a hermetic hollow space can be manufactured under ambient conditions. The use of additional gas or vacuum technology can be avoided. Therefore, the heater assembly can be manufactured in a cost-effective manner.

[0019] The gas composition within the hermetic hollow space may be cheaper compared to solid materials, such as aerogel. The gas composition within the hermetic hollow space may have lower thermal conductivity compared to solid materials. Accordingly, better thermal insulation may be provided. The gas composition within the hermetic hollow space may have lower mass compared to solid materials. Accordingly, a lighter insulating material may be provided.

[0020] Known insulating materials with good thermal insulation properties often require a vacuum. Compared to evacuated hollow spaces, it may be less expensive to manufacture a heater assembly having an airtight hollow space filled with a gaseous composition, preferably ambient air. Vacuum-based insulating materials may be more complex to manufacture. Vacuum-based insulating materials may be more expensive to produce.

[0021] The heater casing may include a wall of the heater casing. The wall of the heater casing may have an outer side facing the outside of the heater assembly. The wall of the heater casing may have an inner side facing the inside of the heater assembly. The inner side of the wall of the heater casing may face the heating chamber.

[0022] The thickness of the wall of the heater casing may be less than about 2 millimeters. The thickness of the wall of the heater casing may be less than 1 millimeter, preferably about 0.8 millimeters. The thickness of one or both of the first and second connecting walls may be less than 1 millimeter, preferably about 0.8 millimeters. With such thin walls, the thermal mass of the heater casing can be minimized. This can further reduce heat loss from the heating chamber.

[0023] One or more of the walls of the heater casing and the first and second connecting walls may be manufactured from a low thermal conductivity material. This may further reduce heat loss from the heating chamber. The walls of the heater casing may include a plastic material or be manufactured from a plastic material. The first and second connecting walls may include a plastic material or be manufactured from a plastic material. The plastic material may include one or all of polyaryletherketone (PAEK), polyetheretherketone (PEEK), and polyphenylenesulfone (PPSU). Preferably, the plastic material includes polyphenylenesulfone (PPSU).

[0024] The inner side of the wall of the heater casing may include a metal coating. The inner side of one or both of the first and second connecting walls may include a metal coating. The metal coating may reduce the emissivity of the inner side of the wall. For example, the emissivity of the PEEK wall may be reduced from about 0.95 to about 0.4. The metal coating may reflect thermal radiation emitted from the heating chamber. The metal coating may provide additional insulation of the heating chamber against the exterior of the heater casing. The metal coating may be a low-emissivity metal coating. The metal coating may include one or more of aluminum, gold, and silver.

[0025] A heating chamber may be configured to accommodate an aerosol-forming material. The heating chamber may include a cavity into which the aerosol-forming material may be inserted. The aerosol-forming material may be part of an aerosol-generating article. The heating chamber may include an opening at the proximal end of the heating chamber for accommodating the aerosol-forming material. The opening may also serve as an air outlet. The heating chamber may include an air inlet at the distal end of the heating chamber.

[0026] The heating chamber may have an elongated shape. The longitudinal axis of the heating chamber may extend between the proximal and distal ends of the heating chamber.

[0027] The heating chamber may be a hollow tube. The hollow tube may be formed as the wall of the heating chamber. The wall of the heating chamber may include a metal or an alloy, or may be manufactured of a metal or an alloy. The wall of the heating chamber may include stainless steel or be manufactured of stainless steel.

[0028] The heater casing can be aligned coaxially around the heating chamber. The heating chamber and the heater casing can have matching shapes. The matching shapes allow for a constant radial distance (d) between the heater casing and the heating chamber.

[0029] The wall of the heater casing may match the shape of the wall of the heating chamber along the longitudinal axis of the heating chamber so that the distance (d) can be approximately constant. For example, the heating chamber may be a hollow tube, and the wall of the heater casing may be a cylindrical wall aligned coaxially around the heating chamber. The distance (d) may be measured radially between the outer diameter of the hollow tube of the heating chamber and the inner diameter of the cylindrical wall of the heater casing. For example, the heating chamber may be a hollow truncated cone, and the wall of the heater casing may be a conical wall aligned coaxially. Those skilled in the art will understand that other types of matching shapes are possible. For example, the matching shape may be curved or wavy, or may include a combination of different shapes along the longitudinal axis of the heating chamber.

[0030] The heating chamber and the heater casing may have a deviated shape. The shape of the wall of the heater casing may deviate to some extent from the shape of the wall of the heating chamber along the longitudinal axis of the heating chamber. The shape of the wall of the heater casing may deviate from the shape of the wall of the heating chamber along the longitudinal axis of the heating chamber such that the distance (d) does not vary by more than 1 millimeter along the longitudinal axis of the heating chamber. For example, the heating chamber may be a right-sided circular hollow cylinder, and the wall of the heater casing may be a slightly conical hollow cylinder aligned coaxially around the heating chamber. Due to the conical shape of the wall of the heater casing, the distance (d) may vary by less than 1 millimeter along the longitudinal axis of the heating chamber.

[0031] The outer diameter of the heater casing can be measured in a direction perpendicular to the longitudinal axis of the heating chamber. The outer diameter of the heater casing can be 12 to 20 millimeters, preferably about 17 millimeters.

[0032] The outer diameter of the heating chamber can be measured in a direction perpendicular to the longitudinal axis of the heating chamber. The ratio of the outer diameter of the heater casing to the outer diameter of the heating chamber can be 2 to 3.5, preferably about 2.75.

[0033] The heating chamber may include a heating element.

[0034] The heating element may be arranged at least partially around the heating chamber. The heating element may be arranged at least partially around the wall of the heating chamber. Preferably, the heating element is arranged to completely coaxially surround the outer circumference of the heating element wall. The heating element may be arranged along at least a portion of the longitudinal axis of the heating chamber.

[0035] The heating element may include one or more electrically conductive tracks on an electrically insulating substrate. One or more electrically conductive tracks may be resistance heating tracks. One or more electrically conductive tracks may be configured as susceptors to be inductively heated. The electrically conductive substrate may be a flexible substrate.

[0036] The heating element can be flexible and can be wrapped around the heating chamber. The heating element can be arranged between the heating chamber and the heater casing.

[0037] In all embodiments of the present invention, the heating element may comprise an electrically resistive material. Suitable electrically resistive materials include, but are not limited to, semiconductors such as doped ceramics, electrically “conductive” ceramics (e.g., molybdenum disilicide), carbon, graphite, metals, metal alloys, and composite materials composed of ceramic materials and metal materials. Such composite materials may comprise doped ceramics or undoped ceramics.

[0038] As described, in any one of the embodiments of the present disclosure, the heating element may be part of the heating chamber of a heater assembly for an aerosol generating device. The heater assembly may include an internal heating element or an external heating element, or both internal and external heating elements, wherein “internal” and “external” are based on the aerosol forming substrate. The internal heating element may take any suitable form. For example, the internal heating element may take the form of a heating blade. Alternatively, the internal heater may take the form of a casing or substrate having different electrically conductive parts, or an electrically resistive metal tube. Alternatively, the internal heating element may be one or more heating needles or rods passing through the center of the aerosol forming substrate. Other alternatives include heating wires or filaments, for example, nickel-chromium (Ni-Cr), platinum, tungsten, or alloy wires, or heating plates. Optionally, the internal heating element may be deposited in or on a rigid carrier material. In one such embodiment, the electrically resistive heating element may be formed using a metal having a defined relationship between temperature and resistivity. In such an exemplary device, the metal may be formed as a track on a suitable insulating material, such as a ceramic material, and then interposed within another insulating material, such as glass. A heater formed in this manner can be used to perform both heating a heating element and monitoring the temperature of the heating element during operation.

[0039] The external heating element may take any suitable form. For example, the external heating element may take the form of one or more flexible heating foils on a dielectric substrate such as polyimide. The flexible heating foils may be shaped to match the outer periphery of the substrate receiving cavity. Alternatively, the external heating element may take the form of a metal grid or grids, a flexible printed circuit board, a molded interconnect device (MID), a ceramic heater, or a flexible carbon fiber heater, or may be formed using a coating technique such as plasma vapor deposition on a substrate of a suitable shape. Additionally, the external heating element may be formed using a metal having a defined relationship between temperature and resistivity. In such an exemplary device, the metal may be formed as a track between two layers of a suitable insulating material. The external heating element formed in this manner may be used for both heating the external heating element and monitoring the temperature of the external heating element during operation.

[0040] The heating element advantageously heats the aerosol-forming substrate by heat conduction. The heating element may be in at least partial contact with the substrate or the carrier on which the substrate is deposited. Alternatively, heat from either the internal or external heating element may be conducted to the substrate by a thermally conductive element.

[0041] During operation, the aerosol-forming material may be completely contained within the aerosol generator. In this case, the user may puff on the mouthpiece of the aerosol generator. Alternatively, during operation, the smoking article containing the aerosol-forming material may be partially contained within the aerosol generator. In this case, the user may puff the smoking article directly.

[0042] The heating element may be configured as an induction heating element. The induction heating element may include an induction coil and a susceptor. Generally, the susceptor is a material capable of generating heat when penetrated by an alternating magnetic field. According to the present invention, the susceptor may be electrically conductive or magnetic, or both electrically conductive and magnetic. An alternating magnetic field generated by one or more induction coils heats the susceptor, which then transfers heat to an aerosol-forming substrate to form an aerosol. Heat transfer may be primarily by conduction of heat. Such heat transfer is best when the susceptor is in close thermal contact with the aerosol-forming substrate. When an induction heating element is used, the induction heating element may be configured as an internal heating element as described herein or as an external heater as described herein. When the induction heating element is configured as an internal heating element, the susceptor element is preferably configured as a pin or blade for penetrating the aerosol-generating article. When the induction heating element is configured as an external heating element, the susceptor element is preferably configured as a cylindrical susceptor that at least partially surrounds the cavity or forms the sidewalls of the cavity.

[0043] The heating chamber may include a central region containing a heating element. The term central region refers to the longitudinal direction. The heating chamber may additionally include a proximal region and a distal region. The proximal region and the distal region may be spaced apart from the heating element in the longitudinal direction. During use, the proximal and distal regions may be colder than the central region of the heating chamber. The first and second connecting walls may contact the heating chamber in the proximal and distal regions, respectively. Thus, the first and second connecting walls may contact the heating chamber at the coldest point of the heating chamber during use. Accordingly, heat loss from the heating chamber to the connecting walls and the heater casing may be further reduced. Insulation may be further improved.

[0044] The walls of the heating chamber can be manufactured from stainless steel. This can beneficially enhance the effect, allowing the proximal and distal regions to be colder than the central region of the heating chamber during use.

[0045] The present invention also relates to an aerosol generating device comprising a heater assembly as described herein.

[0046] Preferably, the aerosol generator includes a power supply unit configured to supply power to a heating element. The power supply unit preferably includes a power source. Preferably, the power source is a battery, such as a lithium-ion battery. Alternatively, the power source may be another type of charge storage device, such as a capacitor. The power source may require recharging. For example, the power source may have a capacity sufficient to continuously generate an aerosol for a period of about 6 minutes, or for a period that is a multiple of 6 minutes. In another embodiment, the power source may have a capacity sufficient to allow a predetermined number of puffings or individual activations of the heater assembly.

[0047] The power supply unit may include control electronics. The control electronics may include a microcontroller. The microcontroller may preferably be a programmable microcontroller. The electrical circuit may include additional electronic components. The electrical circuit may be configured to regulate the power supply to the heater assembly. Power may be supplied to the heater assembly continuously after the system is activated, or intermittently, for example, whenever puffing occurs. Power may be supplied to the heater assembly in the form of pulses of current.

[0048] The present invention also relates to an aerosol generating system comprising an aerosol generating device as described herein and an aerosol forming substrate configured to be at least partially inserted into a heating chamber. The aerosol forming substrate may be part of an aerosol generating article, and the aerosol generating article may be configured to be at least partially inserted into a heating chamber.

[0049] As used herein, the term “aerosol-forming substrate” refers to a substrate capable of releasing a volatile compound capable of forming an aerosol. Volatile compounds may be released by heating or burning the aerosol-forming substrate. As an alternative to heating or burning, in some cases, volatile compounds may be released by chemical reactions or by mechanical stimulation such as ultrasound. The aerosol-forming substrate may be solid or liquid, or may contain both solid and liquid components. The aerosol-forming substrate may be part of an aerosol-generating article.

[0050] As used herein, the term “aerosol generating article” refers to an article comprising an aerosol-forming substrate capable of releasing a volatile compound capable of forming an aerosol. The aerosol generating article may be single-use.

[0051] As used herein, the term “aerosol generating device” refers to a device that generates an aerosol by interacting with an aerosol-forming substrate. An aerosol generating device may interact with an aerosol generating article comprising an aerosol-forming substrate and / or a cartridge comprising an aerosol-forming substrate. In some embodiments, an aerosol generating device may heat the aerosol-forming substrate to facilitate the release of volatile compounds from the substrate. An electrically operated aerosol generating device may include a nebulizer, such as an electric heater, that heats the aerosol-forming substrate to form an aerosol.

[0052] As used herein, the term “aerosol generating system” refers to a combination of an aerosol generating device and an aerosol forming substrate. Where the aerosol forming substrate forms part of an aerosol generating article, the aerosol generating system refers to a combination of an aerosol generating article and an aerosol generating device. In an aerosol generating system, the aerosol forming substrate and the aerosol generating device cooperate to generate an aerosol.

[0053] A non-limiting, non-comprehensive list of examples is provided below. Any one or more of the features of these embodiments may be combined with any one or more of the features of other embodiments, embodiments, or modes described herein.

[0054] Example A: As a heater assembly for an aerosol generating device,

[0055] A heating chamber for heating an aerosol-forming substrate;

[0056] A heater casing arranged around the heating chamber and spaced radially from the heating chamber;

[0057] The first connecting wall and the second connecting wall; and

[0058] A heater assembly comprising the heating chamber, the heater casing, and a hermetic hollow space defined between the first and second connecting walls.

[0059] Example B: A heater assembly in which, in Example A, the distance between the heating chamber and the heater casing is 2.5 millimeters to 7 millimeters.

[0060] Example C: A heater assembly in Example B, wherein the distance between the heating chamber and the heater casing is 3.5 millimeters to 6 millimeters, preferably about 4.6 millimeters.

[0061] Example D: In any one of the previous examples, a heater assembly in which the hermetic hollow space is filled with a gas composition at ambient pressure.

[0062] Example E: In Example D, the heater assembly in which the hermetic hollow space is filled with ambient air.

[0063] Example F: In any one of the previous examples, a heater assembly in which the connecting wall sealably connects the heater casing to the outer wall of the heating chamber.

[0064] Example G: A heater assembly in any one of the previous examples, wherein the connecting wall is oriented perpendicular to the longitudinal axis of the heating chamber.

[0065] Example H: In any one of the previous examples, the heating chamber is a heater assembly having an elongated shape.

[0066] Example I: In Example H, the heating chamber is a hollow tube, a heater assembly.

[0067] Example J: In Example H or Example I, the heating chamber includes a central region, and the heating element is,

[0068] Proximal area; and

[0069] Including the distal region,

[0070] The above proximal region and the above distal region are spaced apart from the heating element in the longitudinal direction, and

[0071] The first and second connecting walls are a heating assembly that contacts the heating chamber in the proximal and distal regions, respectively.

[0072] Example K: In any one of the previous examples, a heater assembly in which a heating element is at least partially arranged around the heating chamber.

[0073] Example L: In any one of the previous examples, the heating element comprises one or more electrically conductive tracks on an electrically insulating substrate, a heater assembly.

[0074] Example M: ​​In Example L, the heating element is flexible and is wrapped around the heating chamber, forming a heater assembly.

[0075] Example N: In any one of Examples K to M, the heating element is arranged between the heating chamber and the heater casing, forming a heater assembly.

[0076] Example O: A heater assembly in which, in any one of the previous examples, the ratio of the outer diameter of the heater casing to the outer diameter of the heating chamber is 2 to 3.5.

[0077] Example P: A heater assembly in which, in any one of the previous examples, the outer diameter of the heater casing is 12 to 20 millimeters, preferably about 17 millimeters.

[0078] Example Q: A heater assembly in which, in any one of the previous examples, the inner side of the wall surface of the heater casing comprises a metal coating.

[0079] Example R: In any one of the previous examples, a heater assembly in which the wall of the heating chamber comprises stainless steel.

[0080] Example S: A heater assembly in which, in any one of the previous examples, the thickness of the wall of the heater casing and one or more of the first and second connecting walls is less than 2 millimeters, preferably about 0.8 millimeters.

[0081] Example T: A heater assembly in which, in any one of the previous examples, the wall of the heater casing and one or more of the first and second connecting walls comprise a plastic material, preferably polyaryletherketone (PAEK), polyetheretherketone (PEEK), or polyphenylenesulfone (PPSU), more preferably polyphenylenesulfone (PPSU).

[0082] Example U: An aerosol generating device comprising a heating assembly according to any one of the previous examples.

[0083] Example V: An aerosol generating system comprising an aerosol generating device according to Example U, and an aerosol generating article configured to be at least partially inserted into the heating chamber.

[0084] Example W: An aerosol generating system in Example V, wherein the system comprises an aerosol generating article, the aerosol generating article comprises an aerosol forming substrate, and the aerosol generating article is configured to be at least partially inserted into the heating chamber.

[0085] The features described in relation to one embodiment may be equally applied to other embodiments of the present invention. Brief explanation of the drawing

[0086] The present invention will be further described merely by example with reference to the accompanying drawings. FIG. 1 shows one embodiment of a heater assembly for an aerosol generating device. Figure 2 shows one embodiment of a heating chamber of a heater assembly. FIG. 3 shows one embodiment of a heater assembly for an aerosol generating device. FIG. 4 shows one embodiment of an aerosol generating device. FIG. 5 shows one embodiment of an aerosol generating device. Specific details for implementing the invention

[0087] In FIG. 1a, FIG. 1 schematically illustrates a heater assembly (10). The heater assembly (10) includes a heating chamber (12) for heating an aerosol-forming substrate. The heating chamber (12) has an elongated shape. The heating chamber (12) includes a wall of a heating chamber (14) that surrounds a cavity for inserting the aerosol-forming substrate. The wall of the heating chamber (14) forms a hollow tube. The heater assembly (10) further includes a heater casing. The heater casing is arranged coaxially around the heating chamber (12). The heater casing includes a cylindrical wall of a heater casing (16). The heater casing is further arranged radially spaced from the heating chamber (12) at a distance (d). The distance (d) can be measured radially between the outer diameter of the hollow tube formed by the wall of the heating chamber (14) and the inner diameter of the cylindrical wall of the heater casing (16). The wall of the heating chamber (14) and the wall of the heater casing (16) may have a matching shape. Accordingly, the distance (d) is constant along the longitudinal axis of the heating chamber (12).

[0088] The heater assembly (10) further includes a first connecting wall (18) at the proximal end of the heater assembly (10). The heater assembly (10) further includes a second connecting wall (20) at the distal end of the heater assembly (10). The first and second connecting walls (18, 20) are oriented perpendicular to the longitudinal axis of the heating chamber (12). The heater assembly (10) further includes an airtight hollow space (22). The airtight hollow space (22) is defined between the wall of the heating chamber (14), the wall of the heater casing (16), and the first and second connecting walls (18, 20).

[0089] FIG. 2 illustrates one embodiment of a heating chamber (12). The heating chamber (12) includes a central region containing a heating element. The heating element is partially arranged around the heating chamber (12). The walls of the heating chamber (14) are metal tubes. The heating element is flexible and wraps around the metal tubes. The heating element includes an electrically conductive heating track (24) on an electrically insulating flexible substrate (26). In the illustrated embodiment, the proximal and distal edge portions of the flexible substrate (26) are not covered by the heating track (24). In another embodiment, different regions or even the entire surface of the flexible substrate (26) may be covered by the heating track (24). The proximal region (28) and distal region (30) of the heating chamber (12) are spaced from the heating element in the longitudinal direction.

[0090] FIG. 3 shows an embodiment of a heater assembly (10) including the heating chamber (12) of FIG. 2. A heating element is arranged between the heating chamber (12) and the heater casing.

[0091] The first and second connecting walls (18, 20) seal the walls of the heater casing (16) with the walls of the heating chamber (14), thereby sealing the airtight hollow space (22).

[0092] The first and second connecting walls (18, 20) contact the heating chamber (12) in the proximal and distal regions (28, 30), respectively. The first and second connecting walls (18, 20) contact the heating chamber (12) at a location spaced apart from the heating element. Thus, the first and second connecting walls (18, 20) contact the heating chamber (12) at the coldest point of the heating chamber when heated during use. Accordingly, heat loss due to heat transport from the heating chamber (12) to the connecting walls (18, 20) and the heater casing via heat conduction is further reduced. Insulation can be further improved.

[0093] The inner side of the wall of the heater casing (16) includes a metal coating (32). The metal coating (32) can reflect heat emitted from the heating chamber (12) back toward the heating chamber. Accordingly, the thermal insulation of the heating chamber against the outside of the heater casing can be improved.

[0094] The distance (d) is measured radially between the heating element on the outer side of the wall of the heating chamber (14) and the metal coating (32) on the inner side of the wall of the heater casing (16).

[0095] FIG. 4 illustrates an embodiment of an aerosol generating device comprising the heater assembly (10) of FIG. 3. The aerosol generating device further comprises a power supply unit. The power supply unit comprises a power source (34) and a control electronic device (36). The power source (34) may be a rechargeable battery. In the embodiment of FIG. 4, the wall of the heater casing (16) forms part of the outer housing (38) of the aerosol generating device.

[0096] In the opening (40), the aerosol-forming material can be inserted at least partially into the heating chamber (12).

[0097] FIG. 5 shows an embodiment of an aerosol generating device including the heater assembly (10) of FIG. 3. Unlike the embodiment of FIG. 4, in the embodiment of FIG. 5, the heater assembly (10) is arranged within a separate external housing (38) of the aerosol generating device.

Claims

Claim 1 A heater assembly for an aerosol generating device, comprising: a heating chamber for heating an aerosol forming substrate; a heater casing arranged around the heating chamber and arranged radially spaced apart from the heating chamber; a first connecting wall and a second connecting wall; and a hermetic hollow space defined between the heating chamber, the heater casing, and the first and second connecting walls, wherein the hermetic hollow space is filled with a gaseous composition at ambient pressure, and a heating element is arranged at least partially around the heating chamber, and the first and second connecting walls sealably connect the heater casing to the outer wall of the heating chamber, and the walls of the heater casing and the first and second connecting walls comprise a plastic material, wherein the plastic material comprises at least one of polyaryletherketone (PAEK), polyetheretherketone (PEEK), and polyphenylenesulfone (PPSU), and the inner side of the walls of the heater casing comprises a metal coating. Claim 2 A heater assembly according to claim 1, wherein the distance between the heating chamber and the heater casing is 2.5 millimeters to 7 millimeters. Claim 3 A heater assembly according to paragraph 2, wherein the distance between the heating chamber and the heater casing is 3.5 millimeters to 6 millimeters. Claim 4 A heater assembly according to any one of claims 1 to 3, wherein the airtight hollow space is filled with ambient air. Claim 5 delete Claim 6 A heater assembly according to any one of claims 1 to 3, wherein the first and second connecting walls are oriented perpendicular to the longitudinal axis of the heating chamber. Claim 7 In any one of claims 1 to 3, the heating chamber is a heater assembly having an elongated shape. Claim 8 A heater assembly according to claim 7, wherein the heating chamber comprises a central region including a heating element; a proximal region; and a distal region, wherein the proximal region and the distal region are spaced apart from the heating element in the longitudinal direction, and the first and second connecting walls are in contact with the heating chamber in the proximal and distal regions, respectively. Claim 9 A heater assembly according to any one of claims 1 to 3, wherein the heating element comprises one or more electrically conductive tracks on an electrically insulating substrate, optionally the heating element is flexible and wrapped around the heating chamber, and optionally the heating element is arranged between the heating chamber and the heater casing. Claim 10 A heater assembly according to any one of claims 1 to 3, wherein the ratio of the outer diameter of the heater casing to the outer diameter of the heating chamber is 2 to 3.

5. Claim 11 A heater assembly according to any one of claims 1 to 3, wherein the outer diameter of the heater casing is 12 millimeters to 20 millimeters. Claim 12 A heater assembly according to any one of claims 1 to 3, wherein the wall of the heating chamber comprises stainless steel. Claim 13 A heater assembly according to any one of claims 1 to 3, wherein the thickness of the wall of the heater casing and one or more of the first and second connecting walls is less than 2 millimeters. Claim 14 delete Claim 15 An aerosol generating device comprising a heating assembly according to any one of paragraphs 1 to 3. Claim 16 An aerosol generating system comprising an aerosol generating device according to claim 15, and an aerosol forming substrate configured to be at least partially inserted into the heating chamber. Claim 17 In claim 16, the system comprises an aerosol generating article, wherein the aerosol generating article comprises an aerosol forming substrate, and the aerosol generating article is configured to be at least partially inserted into the heating chamber. Claim 18 delete

Images