Aerosol generating device having a heater with a cooling zone

Abstract

The present invention relates to a heater assembly for an aerosol-generating device. The heater assembly includes an elongated heating chamber for heating an aerosol-forming substrate. The heater assembly further includes a heating element disposed about the heating chamber. The heating chamber has a first length, and the heating element has a second length. The length of the heating chamber is greater than the length of the heating element, such that a proximal distance exists between a proximal end of the heating chamber and a proximal end of the heating element. The present invention further relates to an aerosol-generating device including the heater assembly, and to an aerosol-generating system including the aerosol-generating device and the aerosol-forming substrate.

Description

Technical 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 further relates to an aerosol-generating system comprising an aerosol-generating device and an aerosol-forming substrate. Background Art

[0002] An aerosol-generating device for generating an inhalable vapor is known. Such a device can heat an aerosol-forming substrate contained in an aerosol-generating article without burning the aerosol-forming substrate. The aerosol-generating article can have a rod shape to facilitate insertion of the aerosol-generating article into a heating chamber of the aerosol-generating device. A heating element is typically disposed in or around the heating chamber to heat the aerosol-forming substrate after the aerosol-generating article is inserted into the heating chamber of the aerosol-generating device.

[0003] Heat generated by the heating element may be inadvertently dissipated from the heating chamber. The heat may be dissipated to the environment or other components of the aerosol generating system. The heat may be inadvertently dissipated from the heating chamber via free air convection. The heat may be inadvertently dissipated from the heating chamber by heat conduction via components of the aerosol generating device. The heat may be inadvertently dissipated from the heating chamber by heat conduction via components of the aerosol generating device (for example, via the aerosol-forming substrate). The heat dissipated from the heating chamber may cause heating of components of the device that are not intended to be heated. For example, the housing of the device to be grasped by the user may become uncomfortably hot. The heat dissipated from the heating chamber may cause heat loss within the heating chamber. The heat loss within the heating chamber may result in less efficient heating. Excessive energy may be required to heat the heating chamber to the desired temperature.

[0004] An aerosol-generating article may comprise a substrate portion and an adjacent filter portion. The substrate portion may be located at the distal end of the article and may comprise an aerosol-forming substrate. The filter portion may be located at the proximal end of the article and may comprise a mouthpiece filter, such as a cellulose acetate filter. If excessive heat is dissipated from the heated substrate portion toward the mouthpiece filter during use, potentially harmful components may be generated within the mouthpiece filter. If the larger proximal portion of the substrate portion is not sufficiently heated during use, aerosol generated in the distal portion of the substrate portion may inadvertently condense within the cool proximal portion of the substrate portion before reaching the user's mouth. Summary of the Invention

[0005] It would be desirable to have an aerosol-generating device that reduces heating of portions of an aerosol-generating article other than the substrate portion. It would be desirable to have an aerosol-generating device that avoids condensation of a significant amount of aerosol in a proximal portion of the substrate portion.

[0006] It would also be desirable to have an aerosol generating device that reduces heat loss from the heating chamber. It would be desirable to have the heating chamber thermally insulated relative to other components of the aerosol generating device. It would be desirable to have an aerosol generating device that reduces the heating of the outer housing of the device to be handled by a user.

[0007] According to an embodiment of the present invention, a heater assembly for an aerosol-generating device is provided. The heater assembly may include an elongated heating chamber for heating an aerosol-forming substrate. The heater assembly may further include a heating element disposed about the heating chamber. The heating chamber may have a first length, and the heating element may have a second length. The length of the heating chamber may be greater than the length of the heating element, such that a proximal distance exists between a proximal end of the heating chamber and a proximal end of the heating element.

[0008] According to an embodiment of the present invention, a heater assembly for an aerosol-generating device is provided. The heater assembly includes an elongated heating chamber for heating an aerosol-forming substrate. The heater assembly further includes a heating element disposed about the heating chamber. The heating chamber has a first length, and the heating element has a second length. The length of the heating chamber is greater than the length of the heating element, such that a proximal distance exists between a proximal end of the heating chamber and a proximal end of the heating element.

[0009] By providing a proximal distance, during use, the proximal end of the heating chamber can be heated to a lower temperature than the rest of the heating chamber surrounded by the heating element. For example, the proximal end of the heating chamber can be heated to a lower temperature than the longitudinal center region of the heating chamber. A proximal "cold zone" of the heating chamber can be located between the proximal end of the heating element and the proximal end of the heating chamber. During use, the temperature of the cold zone can be lower than the temperature of the longitudinal center of the heating chamber. During use, due to heat transfer within the heating chamber, the temperature of the cold zone can be significantly higher than the temperature outside the heating chamber.

[0010] The temperature at the longitudinal center of the cold zone may be between 25% and 95% of the temperature at the longitudinal center of the heating chamber. The temperature at the longitudinal center of the cold zone may be between 30% and 60% of the temperature at the longitudinal center of the heating chamber. The temperature at the longitudinal center of the cold zone may be between 35% and 50% of the temperature at the longitudinal center of the heating chamber. The temperature at the longitudinal center of the cold zone may be approximately 45% of the temperature at the longitudinal center of the heating chamber. The maximum temperature of the heating chamber may be between 240°C and 280°C, preferably 260°C. The coldest point of the cold zone may be between 45°C and 85°C, preferably 65°C.

[0011] When the aerosol-forming substrate is inserted into the heating chamber, the proximal portion of the aerosol-forming substrate may be located in the cold zone. The proximal portion of the aerosol-forming substrate located in the cold zone may be sufficiently heated such that condensation of aerosol in the proximal portion of the aerosol-forming substrate may be reduced or avoided. The proximal portion of the aerosol-forming substrate located in the cold zone may be heated to a temperature lower than that of the distal portion of the aerosol-forming substrate, such that inadvertent overheating of components located near the proximal end of the aerosol-forming substrate may be reduced or avoided.

[0012] The aerosol-forming substrate may be a substrate portion of an aerosol-generating article. By being proximal, heating of portions of the aerosol-generating article other than the substrate portion may be reduced or avoided. Inadvertent heating of the mouthpiece of the aerosol-generating article may be reduced or avoided.

[0013] By providing a proximal distance, the proximal end of the heating chamber may become less hot during use. Heat loss from the less hot proximal end of the heating chamber to one or both of the environment and other components of the aerosol generating device or system may be less. The proximal distance may improve thermal insulation of the heating chamber relative to other components of the aerosol generating device or system. The proximal distance may provide an aerosol generating device that reduces the heating of the outer housing of the device when it is to be handled by a user.

[0014] The proximal distance may be between 0.1 mm and 4 mm, preferably between 0.5 mm and 4 mm, more preferably between 1 mm and 3 mm, more preferably between 1.5 mm and 2.5 mm, and most preferably about 2 mm. These distances may be long enough to beneficially reduce heat loss and the generation of potentially harmful components in the cold zone. At the same time, these distances may still be small enough so that the aerosol-forming substrate located in the cold zone can still be sufficiently heated to reduce or avoid aerosol condensation in the proximal portion of the aerosol-forming substrate located in the cold zone.

[0015] The inner diameter of the heating chamber can be defined in a direction orthogonal to the longitudinal axis of the heating chamber. The inner diameter of the heating chamber can be between 4 mm and 9 mm, preferably between 4.5 mm and 8 mm. The inner diameter of the heating chamber can be between 4.5 mm and 6.3 mm, more preferably between 5.2 mm and 5.5 mm, and most preferably about 5.35 mm. The inner diameter of the heating chamber can be between 6.8 mm and 7.5 mm, preferably between 7.2 mm and 7.4 mm, and more preferably about 7.3 mm or 7.35 mm.

[0016] The length of the heating chamber can be measured along the longitudinal axis of the heating chamber. The length of the heating chamber can be between 10 mm and 35 mm, preferably between 18 mm and 26 mm, more preferably between 20 mm and 24 mm, and most preferably about 22 mm. The length of the heating chamber can be between 10 mm and 14 mm, preferably between 11 mm and 13 mm, and more preferably about 12 mm.

[0017] The length of the heating element can be measured in a direction parallel to the longitudinal axis of the heating chamber. The length of the heating element can be between 10 mm and 21 mm, preferably between 17 mm and 18 mm, and more preferably about 17 mm. The length of the heating element can be between 10 mm and 13 mm, preferably about 11 mm.

[0018] The heater assembly may include a distal distance between a distal end of the heating chamber and a distal end of the heating element.

[0019] By providing a distal distance, the distal end of the heating chamber may become less hot during use. Heat loss from the cooler distal end to one or both of the environment and other components of the aerosol generating device may be less. The distal distance may reduce heat loss from the heating chamber. The distal distance may improve thermal insulation of the heating chamber relative to other components of the aerosol generating device. The distal distance may provide an aerosol generating device that reduces heating of the outer housing of the device when it is to be handled by a user.

[0020] The distal distance may be between 1 mm and 6 mm, preferably between 1.5 mm and 6 mm, more preferably between 2 mm and 4 mm, more preferably between 2.5 mm and 3.5 mm, and most preferably about 3 mm. The distal distance may be about 1 mm.

[0021] According to an embodiment, the length of the heating chamber is 22 mm, the inner diameter of the heating chamber is 5.35 mm, the length of the heating element is 17 mm, the proximal distance is 2 mm, and the distal distance is 3 mm. According to an embodiment, the length of the heating chamber is between 19 mm and 22 mm, the inner diameter of the heating chamber is 5.35 mm, the length of the heating element is between 17 mm and 20 mm, and the proximal distance is 2 mm.

[0022] According to an embodiment, the length of the heating chamber is 12 mm, the inner diameter of the heating chamber is between 7.0 mm and 7.35 mm, the length of the heating element is 10 mm, the proximal distance is 1 mm, and the distal distance is 1 mm. According to an embodiment, the length of the heating chamber is between 11 mm and 12 mm, the inner diameter of the heating chamber is between 7.0 mm and 7.35 mm, the length of the heating element is between 10 mm and 11 mm, and the proximal distance is 1 mm.

[0023] As used herein, the terms "upstream" and "front" as well as "downstream" and "rear" are used to describe the relative position of components or portions of components of an aerosol-generating device with respect to the direction of air flowing through the aerosol-generating device during use. An aerosol-generating device according to the present invention comprises a proximal end through which, in use, aerosol exits the device. The proximal end of the aerosol-generating device may also be referred to as the mouth end or downstream end. The mouth end is downstream from the distal end. The distal end of the aerosol-generating article may also be referred to as the upstream end. Components or portions of components of an aerosol-generating device may be described as being upstream or downstream of each other based on their relative position with respect to the airflow path of the aerosol-generating device.

[0024] The proximal end of a heater assembly according to the present invention is configured to be disposed within an aerosol-generating device in a direction toward the mouth end or downstream end of the device. The distal end of a heater assembly according to the present invention is configured to be disposed within an 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.

[0025] The proximal distance may be measured in a direction parallel to the longitudinal axis of the heating chamber.The distal distance may be measured in a direction parallel to the longitudinal axis of the heating chamber.

[0026] The heater assembly may include a heater housing. The heater housing may include a wall of the heater housing. The heater housing may be arranged around the heating chamber. The heater housing may be arranged radially spaced from the heating chamber. The heater assembly may further include a first connecting wall. The heater assembly may further include a second connecting wall. The heater assembly may further include an airtight hollow space. The airtight hollow space may be defined between the heating chamber, the heater housing, and the first connecting wall and the second connecting wall. The heating chamber may include a wall of the heating chamber. Each of the first connecting wall and the second connecting wall may extend between the wall of the heating chamber and the wall of the heater housing. The first connecting wall and the second connecting wall may sealingly connect the heater housing to an outer wall of the heating chamber. The connecting walls may be oriented perpendicular to a 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.

[0027] The heating chamber may be configured to receive an aerosol-forming substrate. The heating chamber may include a cavity into which the aerosol-forming substrate may be inserted. The aerosol-forming substrate may be part of an aerosol-generating article. The heating chamber may include an opening at a proximal end of the heating chamber for receiving the aerosol-forming substrate. The opening may also serve as an air outlet. The heating chamber may include an air inlet at a distal end of the heating chamber.

[0028] The heating chamber may have an elongated shape.The longitudinal axis of the heating chamber may extend between a proximal end and a distal end of the heating chamber.

[0029] The heating chamber may be a hollow tube. The hollow tube may be formed by the walls of the heating chamber. The walls of the heating chamber may include or be made of a metal or alloy. The walls of the heating chamber may include or be made of stainless steel.

[0030] The heating element may be arranged at least partially around the wall of the heating chamber. Preferably, the heating element is arranged completely coaxially around the outer periphery of the wall of the heating chamber. The heating element may be arranged along at least a portion of the longitudinal axis of the heating chamber.

[0031] The heating chamber may include a central region containing the heating element. The term central region refers to the longitudinal direction. The heating chamber may further include a proximal region and a distal region. One or both of the proximal region and the distal region may be spaced apart from the heating element in the longitudinal direction by one or both of a corresponding proximal distance and a corresponding distal distance. A proximal cold zone may be defined by the proximal distance. A distal cold zone may be defined by the distal distance. During use, one or both of the proximal cold zone and the distal cold zone may be cooler than the central region of the heating chamber. The first connecting wall and the second connecting wall may contact the heating chamber in the proximal cold zone and the distal cold zone, respectively. Therefore, during use, the first connecting wall and the second connecting wall may contact the heating chamber at the coldest point of the heating chamber. This may further reduce heat loss from the heating chamber to the connecting walls and the heater housing. This may further improve thermal insulation.

[0032] The walls of the heating chamber may be made of stainless steel. This may advantageously enhance the effect that during use, the proximal and distal cold zones may be cooler than the central area of ​​the heating chamber.

[0033] The heating element may include one or more conductive traces on an electrically insulating substrate. The one or more conductive traces may be resistive heating traces. The one or more conductive traces may be configured as susceptors to be inductively heated. The electrically insulating substrate may be a flexible substrate.

[0034] The heating element may be flexible and may be wrapped around the heating chamber.The heating element may be arranged between the heating chamber and the heater housing.

[0035] In all aspects of the present disclosure, the heating element may comprise a resistive material. Suitable resistive materials include, but are not limited to, semiconductors such as doped ceramics, "conductive" ceramics (e.g., molybdenum disilicide), carbon, graphite, metals, metal alloys, and composite materials made from ceramic and metallic materials. Such composite materials may include doped or undoped ceramics.

[0036] As described, in any of the aspects of the present disclosure, the heating element may be part of a 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, where "internal" and "external" refer to 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 sleeve or substrate with different conductive portions, or a resistive metal tube. Alternatively, the internal heating element may be one or more heating needles or rods that extend through the center of the aerosol-forming substrate. Other alternatives include heating wires or filaments, such as Ni-Cr (nickel-chromium), platinum, tungsten or alloy wires, or heating plates. Optionally, the internal heating element may be deposited within or on a rigid carrier material. In one such embodiment, the resistive heating element may be formed using a metal with a defined relationship between temperature and resistivity. In such exemplary devices, the metal may be formed as a trace on a suitable insulating material (e.g., a ceramic material) and then sandwiched between another insulating material (e.g., glass). A heater formed in this manner may be used to heat and monitor the temperature of the heating element during operation.

[0037] The external heating element can take any suitable form. For example, the external heating element can take the form of one or more flexible heating foils on a dielectric substrate (e.g., polyimide). The flexible heating foil can be shaped to be consistent with the periphery of the substrate receiving cavity. Alternatively, the external heating element can take the form of a metal grid, a flexible printed circuit board, a molded interconnect device (MID), a ceramic heater, a flexible carbon fiber heater, or can be formed on a suitable shaped substrate using a coating technique (e.g., plasma vapor deposition). The external heating element can also be formed using a metal with a defined relationship between temperature and resistivity. In such exemplary devices, the metal can be formed as a trace between two layers of suitable insulating material. The external heating element formed in this way can be used to heat and monitor the temperature of the external heating element during operation.

[0038] Advantageously, the heating element heats the aerosol-forming substrate by means of heat conduction. The heating element may at least partially contact the substrate or a carrier on which the substrate is disposed. Alternatively, heat from an internal or external heating element may be conducted to the substrate by a heat conducting element.

[0039] During operation, the aerosol-forming substrate may be completely contained within the aerosol-generating device. In this case, the user may draw on the mouthpiece of the aerosol-generating device. Alternatively, during operation, the smoking article containing the aerosol-forming substrate may be partially contained within the aerosol-generating device. In this case, the user may draw directly on the smoking article.

[0040] The heating element may be configured as an induction heating element. The induction heating element may include an induction coil and a susceptor. Generally, a 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. The alternating magnetic field generated by one or more induction coils heats the susceptor, which then transfers the heat to the aerosol-forming substrate, causing aerosol to form. Heat transfer may be primarily by thermal conduction. This heat transfer is optimal if the susceptor is in close thermal contact with the aerosol-forming substrate. When an induction heating element is employed, the induction heating element may be configured as an internal heating element as described herein or as an external heater as described herein. If 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. If 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 a sidewall of the cavity.

[0041] The present invention further relates to an aerosol generating device comprising a heater assembly as described herein.

[0042] Preferably, the aerosol generating device includes a power supply configured to supply power to the heating element. The power supply preferably comprises a power source. Preferably, the power source is a battery, such as a lithium-ion battery. Alternatively, the power source may be another form of charge storage device, such as a capacitor. The power source may require recharging. For example, the power source may have sufficient capacity to allow continuous aerosol generation for a period of approximately six minutes, or for an integral multiple of six minutes. As another example, the power source may have sufficient capacity to allow a predetermined number of puffs or discrete activations of the heater assembly.

[0043] The power supply may include control electronics. The control electronics may include a microcontroller. The microcontroller is preferably a programmable microcontroller. The circuit may include additional electronic components. The circuit may be configured to regulate power to the heater assembly. Power may be supplied to the heater assembly continuously after system startup, or may be supplied intermittently, such as on a puff-by-puff basis. Power may be supplied to the heater assembly in the form of current pulses.

[0044] The present invention further 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 the heating chamber.

[0045] The aerosol-generating article may comprise a substrate portion comprising an aerosol-forming substrate. The length of the substrate portion may be shorter than or equal to the length of the heating element. The length of the substrate portion may be greater than the length of the heating element. The length of the substrate portion may be greater than the length of the heating element but shorter than the length of the heating chamber. The length of the substrate portion may be equal to or greater than the length of the heating chamber.

[0046] Generally, in an aerosol-generating system as described herein, when the aerosol-generating article is fully inserted into the heating chamber, the proximal cold zone may extend between the proximal end of the heating element and the proximal end of the substrate portion. When the aerosol-generating article is fully inserted into the heating chamber, the proximal end of the heating element may be disposed distally of the proximal end of the substrate portion. When the aerosol-generating article is fully inserted into the heating chamber, the proximal end of the heating chamber may be disposed at the same longitudinal position as the proximal end of the substrate portion. In this case, the proximal distance may be equal to the proximal cold zone. When the aerosol-generating article is fully inserted into the heating chamber, the proximal end of the heating chamber may be disposed distally of the proximal end of the substrate portion.

[0047] The length of the matrix portion may be equal to the length of the heating chamber, and the proximal distance may be equal to the proximal cold zone. If the length of the matrix portion is greater than the length of the heating chamber, the proximal cold zone may be longer than the proximal distance. In this case, the length of the proximal cold zone may be the sum of the proximal distance plus the additional distance between the proximal end of the heating chamber and the proximal end of the matrix portion.

[0048] If the length of the matrix portion is shorter than the length of the heating chamber, the proximal distance may be longer than the proximal cold zone.

[0049] According to an embodiment, the outer diameter of the aerosol generating article is 5.3 mm and the length of the proximal cold zone is between 0.1 mm and 4 mm, preferably between 0.5 mm and 4 mm, more preferably between 1 mm and 3 mm, more preferably between 1.5 mm and 2.5 mm, and most preferably about 2 mm.

[0050] According to an embodiment, the outer diameter of the aerosol-generating article is between 7.0 mm and 7.3 mm, and the length of the proximal cold zone is between 0.1 mm and 2 mm, preferably between 0.5 mm and 1.5 mm, more preferably about 1 mm.

[0051] The length of the substrate portion may be between 10 mm and 35 mm, preferably between 18 mm and 26 mm, more preferably between 20 mm and 24 mm, and most preferably about 22 mm. The outer diameter of the aerosol-generating article may be between 4 mm and 8 mm, preferably about 5.3 mm.

[0052] According to an embodiment, the length of the heating chamber is 22 mm, the inner diameter of the heating chamber is 5.35 mm, the length of the heating element is 17 mm, the proximal distance is 2 mm, and the distal distance is 3 mm, the outer diameter of the aerosol generating article is 5.3 mm, and the length of the matrix portion is between 20 mm and 24 mm, preferably 22 mm.

[0053] The length of the substrate portion may be between 10 mm and 14 mm, preferably between 11 mm and 13 mm, more preferably about 12 mm. The outer diameter of the aerosol-generating article may be between 7 mm and 8 mm, preferably between 7.0 mm and 7.3 mm, more preferably about 7.23 mm.

[0054] According to an embodiment, the length of the heating chamber is 12 mm, the inner diameter of the heating chamber is about 7.3 mm, the length of the heating element is 10 mm, the proximal distance is 1 mm, the distal distance is 1 mm, the outer diameter of the aerosol-generating article is 7.23 mm, and the length of the matrix portion is between 11 mm and 13 mm, preferably 12 mm.

[0055] In an embodiment, the outer diameter of the aerosol-generating article is 5.3 mm, the length of the matrix portion is 20 mm, the inner diameter of the heating chamber is 5.35 mm, the length of the heating element is between 75% and 95% of the length of the matrix portion, the length of the proximal cold zone is between greater than 0% and 20% of the length of the matrix portion, and the length of the distal cold zone is between 5% and 15% of the length of the matrix portion.

[0056] In an embodiment, the outer diameter of the aerosol-generating article is 5.3 mm, the length of the matrix portion is 22 mm, the inner diameter of the heating chamber is 5.35 mm, the length of the heating element is between 68% and 95%, preferably about 77%, of the length of the matrix portion, the length of the proximal cold zone is between greater than 0% and 18%, preferably about 9%, of the length of the matrix portion, and the length of the distal cold zone is between 4.5% and 14%, preferably about 13.6%, of the length of the matrix portion.

[0057] In an embodiment, the outer diameter of the aerosol-generating article is 5.3 mm, the length of the matrix portion is 24 mm, the inner diameter of the heating chamber is 5.35 mm, the length of the heating element is between 62% and 88% of the length of the matrix portion, the length of the proximal cold zone is between greater than 0% and 17%, preferably about 8%, of the length of the matrix portion, and the length of the distal cold zone may be between 4% and 13% of the length of the matrix portion.

[0058] In an embodiment, the outer diameter of the aerosol-generating article is between 7.0 mm and 7.3 mm, the length of the matrix portion is 12 mm, the inner diameter of the heating chamber is between 7.0 mm and 7.4 mm, the length of the heating element is between 67% and 92% of the length of the matrix portion, the length of the proximal cold zone is between greater than 0% and 17%, preferably about 8.3%, of the length of the matrix portion, and the length of the distal cold zone is between 8% and 17% of the length of the matrix portion.

[0059] The present invention further relates to an aerosol-generating article for use with an aerosol-generating device. The aerosol-generating article may be an aerosol-generating article as described herein. The aerosol-generating article may be suitable for use with an aerosol-generating device as described herein.

[0060] As used herein, the term "aerosol-forming substrate" refers to a substrate that is capable of releasing volatile compounds that can form an aerosol. The volatile compounds can be released by heating or burning the aerosol-forming substrate. As an alternative to heating or burning, in some cases, the volatile compounds can be released by a chemical reaction or by mechanical stimulation (such as ultrasound). The aerosol-forming substrate can be solid or liquid, or can include solid and liquid components. The aerosol-forming substrate can be part of an aerosol-generating article.

[0061] As used herein, the term "aerosol-generating article" refers to an article comprising an aerosol-forming substrate that is capable of releasing volatile compounds that can form an aerosol. The aerosol-generating article may be disposable.

[0062] As used herein, the term "aerosol-generating device" refers to a device that interacts with an aerosol-forming substrate to generate an aerosol. The aerosol-generating device may interact with one or both of an aerosol-generating article comprising an aerosol-forming substrate or a cartridge comprising an aerosol-forming substrate. In some examples, the aerosol-generating device may heat the aerosol-forming substrate to facilitate release of volatile compounds from the substrate. Electrically operated aerosol-generating devices may include an atomizer, such as an electric heater, to heat the aerosol-forming substrate to form the aerosol.

[0063] As used herein, the term "aerosol-generating system" refers to the combination of an aerosol-generating device and an aerosol-forming substrate. When the aerosol-forming substrate forms part of an aerosol-generating article, the aerosol-generating system refers to the combination of the aerosol-generating device and the aerosol-generating article. In an aerosol-generating system, the aerosol-forming substrate and the aerosol-generating device cooperate to generate an aerosol.

[0064] 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.

[0065] Example A: A heater assembly for an aerosol-generating device, comprising:

[0066] an elongated heating chamber for heating the aerosol-forming substrate; and

[0067] a heating element arranged around the heating chamber; wherein the heating chamber has a first length and the heating element has a second length, and

[0068] The length of the heating chamber is greater than the length of the heating element, so that there is a proximal distance between the proximal end of the heating chamber and the proximal end of the heating element.

[0069] Example B: The heater assembly of Example A, wherein the proximal distance is between 0.1 mm and 4 mm, preferably between 1 mm and 3 mm, more preferably between 1.5 mm and 2.5 mm, and most preferably about 2 mm.

[0070] Example C: A heater assembly according to Example A or Example B, wherein the ratio of the inner diameter of the heating chamber to the proximal distance is between 2 and 4, preferably between 2.25 and 3.15, more preferably between 2.60 and 2.75, and most preferably about 2.68.

[0071] Example D: The heater assembly of any preceding example, wherein a ratio of the length of the heating chamber to the proximal distance is between 5.5 and 22, preferably between 9 and 13, and more preferably about 11.

[0072] Example E: The heater assembly of any preceding example, wherein the proximal distance is between 6% and 14%, preferably between 8% and 11%, and more preferably about 9%, of the length of the heating chamber.

[0073] Example F: The heater assembly of any of the preceding examples, wherein the length of the heating chamber is between 10 mm and 35 mm, preferably between 18 mm and 26 mm, more preferably between 20 mm and 24 mm, and most preferably about 22 mm.

[0074] Example G: The heater assembly of any preceding example, wherein the length of the heating element is between 15 mm and 21 mm, preferably between 17 mm and 18 mm, and more preferably about 17 mm.

[0075] Example H: A heater assembly according to any of the preceding examples, wherein the inner diameter of the heating chamber is between 4.5 mm and 6.3 mm, preferably between 5.2 mm and 5.5 mm, more preferably about 5.35 mm, or wherein the inner diameter of the heating chamber is between 6.8 mm and 7.5 mm, preferably between 7.2 mm and 7.4 mm, more preferably about 7.3 mm or 7.35 mm.

[0076] Example I: The heater assembly of any preceding example, wherein there is a distal distance between a distal end of the heating chamber and a distal end of the heating element.

[0077] Example J: A heater assembly according to Example I, wherein the distal distance is between 1 mm and 6 mm, preferably between 2 mm and 4 mm, more preferably between 2.5 mm and 3.5 mm, and most preferably about 3 mm.

[0078] Example K: A heater assembly according to Example I or Example J, wherein the ratio of the inner diameter of the heating chamber to the distal distance is between 1 and 3, preferably between 1.5 and 2.1, more preferably between 1.73 and 1.83, and most preferably about 1.78.

[0079] Example L: The heater assembly of any of Examples I to K, wherein a ratio of the length of the heating chamber to the distal distance is between 5 and 11, preferably between 6 and 9, and more preferably about 7.3.

[0080] Example M: ​​The heater assembly of any of Examples I to L, wherein the distal distance is between 9% and 20%, preferably between 12% and 15%, and more preferably about 13.6%, of the length of the heating chamber.

[0081] Example N: The heater assembly of any preceding example, wherein the heating chamber is a hollow tube.

[0082] Example O: The heater assembly of any preceding example, wherein the heating chamber comprises stainless steel.

[0083] Example P: The heater assembly of any preceding example, wherein the heating element comprises one or more electrically conductive traces on an electrically insulating substrate.

[0084] Example Q: The heater assembly of example P, wherein the heating element is flexible and wrapped around the heating chamber.

[0085] Example R: An aerosol-generating device comprising a heater assembly according to any of the preceding examples.

[0086] Example S: An aerosol-generating system comprising an aerosol-generating device according to example R and an aerosol-forming substrate configured to be at least partially inserted into the heating chamber.

[0087] Example T: An aerosol-generating system according to Example S, wherein the system comprises an aerosol-generating article, the aerosol-generating article comprising a substrate portion comprising the aerosol-forming substrate, and wherein the aerosol-generating article is configured to be at least partially inserted into the heating chamber.

[0088] Example U: An aerosol-generating system according to example T, wherein the length of the substrate portion is greater than the length of the heating element.

[0089] Example V: An aerosol generating system according to example U, wherein the length of the substrate portion is equal to or greater than the length of the heating chamber.

[0090] Example W: An aerosol generating system according to any one of examples T to V, wherein the length of the substrate portion is between 15 mm and 35 mm, preferably between 18 mm and 26 mm, more preferably between 20 mm and 24 mm, and most preferably about 22 mm.

[0091] Example X: An aerosol-generating system according to any one of Examples T to W, wherein the outer diameter of the aerosol-generating article is between 4 mm and 6 mm, preferably about 5.3 mm.

[0092] Features described with respect to one embodiment may be equally applicable to other embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0093] The present invention will be further described, by way of example only, with reference to the accompanying drawings, in which:

[0094] Figure 1 a and 1 b show a heater assembly in combination with an aerosol-generating article.

[0095] Figure 2 A heater assembly is shown.

[0096] Figure 3 An aerosol generating device is shown. DETAILED DESCRIPTION

[0097] Figure 1 1a and 1b show an embodiment of a heater assembly 10. The heater assembly 10 comprises an elongated heating chamber 12 for heating an aerosol-forming substrate and a heating element 14 arranged around the heating chamber 12. The length of the heating chamber 12 is greater than the length of the heating element 14, such that a proximal distance dp exists between the proximal end of the heating chamber 12 and the proximal end of the heating element 14.

[0098] The aerosol-generating substrate may be, for example, Figure 1 A portion of an aerosol-generating article 16 is shown in Figures 1a and 1b. The aerosol-generating article 16 comprises a substrate portion 18 comprising an aerosol-forming substrate, and a mouthpiece 20. Figure 1 As indicated by the arrow in a, the heating chamber 12 is configured to receive an aerosol-forming substrate. Figure 1 b shows a configuration in which the substrate portion 18 of the aerosol-generating article 16 is inserted into the heating chamber 12 . Figure 1 b shows an embodiment in which the length of the matrix portion 18 is equal to the length of the heating chamber 12. Therefore, the proximal cold zone extending from the proximal end of the heating element 14 to the proximal end of the matrix portion 18 is equal to the proximal distance dp.

[0099] exist Figure 1 In the embodiments of a and 1b, there is also a distal distance dd between the distal end of the heating chamber 12 and the distal end of the heating element 14. Figure 1 In the embodiments of a and 1b, the proximal distance and the distal distance are substantially equal in length. In other embodiments, the proximal distance and the distal distance may be different in length, or there may be no distal distance.

[0100] Figure 2 An embodiment of a heated heater assembly 10 is shown. A heating chamber 12 includes a central region containing a heating element 14. The heating element 14 is arranged around the heating chamber 12. The walls of the heating chamber 12 are metal tubes. The heating element 14 is flexible and wrapped around the metal tubes. The heating element 14 includes electrically conductive heating traces. The electrically conductive heating traces can function as resistive heating elements, or they can function as inductively heated susceptors. The electrically conductive heating traces are provided on an electrically insulating flexible substrate 22. In the illustrated embodiment, the proximal and distal edge portions of the flexible substrate 22 are not covered by the electrically conductive heating traces. In other embodiments, different regions, or even the entire surface, of the flexible substrate 22 may be covered by the heating traces. The length of the heating element and the proximal and distal ends of the heating element refer to the length of the electrically conductive heating trace and the proximal and distal ends of the electrically conductive heating trace, respectively.

[0101] The proximal and distal regions of the heating chamber 12 are spaced apart from the heating element 14 in the longitudinal direction. A proximal distance dp exists between the proximal end of the heating chamber 12 and the proximal end of the heating element 14. A distal distance dd exists between the distal end of the heating chamber 12 and the distal end of the heating element 14. Figure 2 In an embodiment, the length of the proximal distance dp is less than the distal distance dd.

[0102] The heating element 14 is arranged between the heating chamber 12 and the heater housing of the heater assembly 10. A first connecting wall 24 and a second connecting wall 26 connect the wall of the heater housing 28 to the wall of the heating chamber 12 in a sealing manner.

[0103] The first connecting wall 24 and the second connecting wall 26 contact the heating chamber 12 in the proximal and distal regions, respectively. The first connecting wall 24 and the second connecting wall 26 contact the heating chamber 12 at a location spaced apart from the heating element 14. Therefore, during use, when heated, the first connecting wall 24 and the second connecting wall 26 contact the heating chamber 12 at its coldest point. This further reduces heat losses due to heat transfer from the heating chamber 12 to the connecting walls 24 and 26 and the heater housing via thermal conduction. This further improves thermal insulation.

[0104] Figure 3 Shown include Figure 2 The aerosol-generating device of the embodiment of the heater assembly 10 is shown. The aerosol-generating device further comprises a power supply. The power supply comprises a power source 30 and control electronics 32. The power source 30 may be a rechargeable battery. The aerosol-forming substrate may be at least partially inserted into the heating chamber 12 at the opening 34.

Claims

1. A heater assembly for an aerosol generating device, comprising: heater housing; an elongated heating chamber for heating the aerosol-forming substrate; as well as a heating element disposed around the heating chamber; wherein the heating chamber has a first length and the heating element has a second length, and wherein the length of the heating chamber is greater than the length of the heating element such that there is a proximal distance between a proximal end of the heating chamber and a proximal end of the heating element, wherein the proximal distance is between 0.1 mm and 4 mm, wherein the heater housing is arranged radially spaced apart from the heating chamber, and wherein the heating element is arranged between the heating chamber and the heater housing. 2 . The heater assembly of claim 1 , wherein the proximal distance is between 1 mm and 3 mm. The heater assembly of claim 1 , wherein the proximal distance is between 1.5 mm and 2.5 mm. The heater assembly of claim 1 , wherein the proximal distance is approximately 2 mm. The heater assembly of claim 1 , wherein a ratio of an inner diameter of the heating chamber to the proximal distance is between 2 and 4.

6. The heater assembly of claim 1, wherein a ratio of an inner diameter of the heating chamber to the proximal distance is between 2.25 and 3.

15.

7. The heater assembly of claim 1, wherein a ratio of an inner diameter of the heating chamber to the proximal distance is between 2.60 and 2.

75.

8. The heater assembly of claim 1, wherein a ratio of an inner diameter of the heating chamber to the proximal distance is approximately 2.

68. 9 . The heater assembly of claim 1 , wherein a ratio of the length of the heating chamber to the proximal distance is between 5.5 and 22. 10 . The heater assembly of claim 1 , wherein a ratio of the length of the heating chamber to the proximal distance is between 9 and 13. 11 . The heater assembly of claim 1 , wherein a ratio of the length of the heating chamber to the proximal distance is approximately 11.

12. The heater assembly of claim 1, wherein the proximal distance is between 6% and 14% of the length of the heating chamber.

13. The heater assembly of claim 1, wherein the proximal distance is between 8% and 11% of the length of the heating chamber.

14. The heater assembly of claim 1, wherein the proximal distance is approximately 9% of the length of the heating chamber.

15. The heater assembly of claim 1, wherein there is a distal distance between a distal end of the heating chamber and a distal end of the heating element.

16. The heater assembly of claim 15, wherein the distal distance is between 1 mm and 6 mm.

17. The heater assembly of claim 15, wherein the distal distance is between 2 mm and 4 mm.

18. The heater assembly of claim 15, wherein the distal distance is between 2.5 mm and 3.5 mm.

19. The heater assembly of claim 15, wherein the distal distance is approximately 3 mm.

20. The heater assembly of any one of claims 1 to 19, wherein the heating chamber is a hollow tube.

21. The heater assembly of any one of claims 1 to 19, wherein the heating chamber comprises stainless steel.

22. A heater assembly according to any one of claims 1 to 19, wherein the heating element comprises one or more electrically conductive traces on an electrically insulating substrate.

23. The heater assembly of any one of claims 1 to 19, wherein the heating element is flexible and wrapped around the heating chamber.

24. An aerosol generating device comprising a heater assembly according to any one of claims 1 to 23.

25. An aerosol-generating system comprising an aerosol-generating device according to claim 24 and an aerosol-generating article, the aerosol-generating article comprising a substrate portion comprising an aerosol-forming substrate, wherein the aerosol-generating article is configured to be at least partially inserted into the heating chamber.

26. An aerosol-generating system according to claim 25, wherein when the aerosol-generating article is fully inserted into the heating chamber, a proximal cold zone extends between a proximal end of the heating element and a proximal end of the substrate portion.

27. An aerosol generating system according to claim 25, wherein the length of the substrate portion is greater than the length of the heating element.

Images