Patent Application
20240114975
The present disclosure relates to heating an aerosol-generating article in an aerosol-generating device. The present disclosure relates to managing heat in an aerosol-generating device.
EP 0 858 744 A1 describes a flavor generation piece having a heat conduction tube in which a formed body of solid material for generating a flavor or the like to be inhaled by a user is provided. The flavor generation piece may be inserted into a flavor generation heater so that the heat conduction tube is provided above a gas nozzle for providing a flame. An inner surface of the heat conduction tube is covered with a heat accumulating material layer. The heat accumulating material layer allows a temperature of the formed body in the heat conduction tube to be maintained at a flavor generation temperature for a longer time.
According to an aspect of the present invention, there is provided an aerosol-generating device with an axially extending heating space. The heating space is configured to at least partially receive an aerosol-generating article. The aerosol-generating device comprises a heat receiving surface provided outside of the heating space. The aerosol-generating device comprises a heat storage body and an inner heat conduction body. The heat storage body is provided between the heat receiving surface and the heating space. The inner heat conduction body is provided between the heat storage body and the heating space. A material of the heat storage body has a higher specific heat capacity than a material of the inner heat conduction body. The material of the inner heat conduction body has a higher thermal conductivity than the material of the heat storage body.
The heat storage body may serve as a heat buffer. The heat storage body may take up heat from the heat receiving surface, when the heat receiving surface is heated. The heat taken up by the heat storage body may be provided to the heating space over time to heat the aerosol-generating article provided therein. The heat storage body may take up a certain amount of heat over a first time and release the amount of heat over a second, greater time. For example, the second time may be at least twenty times the first time, or at least fifteen times the first time, or at least ten times the first time, or at least five times the first time, or at least double the first time. Due to the buffer function of the heat storage body, overheating of the heating space may be prevented, when the heat receiving surface is heated to high temperatures. Further, the heat storage body may allow the heating space to maintain an aerosol generation temperature for a longer period of time after heating of the heat receiving surface has stopped.
The inner heat conduction body may facilitate transferring heat stored in the heat storage body towards the heating space, and thus towards an aerosol-generating article at least partially received in the heating space. The inner heat conduction body may distribute the heat to desired regions at the aerosol-generating article in an efficient manner. The inner heat conduction body may guide a flow of heat from the heat storage body.
The material of the heat storage body may have a specific heat capacity between 300 joule per kelvin per kilogram and 1500 joule per kelvin per kilogram, or between 500 joule per kelvin per kilogram and 1200 joule per kelvin per kilogram, or between 600 joule per kelvin per kilogram and 1000 joule per kelvin per kilogram, or between 600 joule per kelvin per kilogram and 800 joule per kelvin per kilogram.
The material of the heat storage body may, for example, be glass or metal. The material of the heat storage body may comprise glass or metal.
One or both of the material of the heat storage body and the material of the inner heat conduction body may have a melting temperature above 800 degrees Celsius, or above 900 degrees Celsius, or above 1000 degrees Celsius, or above 1100 degrees Celsius, or above 1300 degrees Celsius, or above 1500 degrees Celsius. In view of such melting temperatures, the heat storage body and the inner heat conduction body may be prevented from melting upon heating the heat receiving surface. In particular, the heat storage body and the inner heat conduction body may be prevented from melting, when the heat receiving surface is heated by one or more flames, such as a flame generated by a common cigarette lighter.
One or both of the heat storage body and the inner heat conduction body may circumferentially surround the heating space. If the heat storage body circumferentially surrounds the heating space, the heat storage body may store heat circumferentially around the heating space. If the inner heat conduction body circumferentially surrounds the heating space, heat may be distributed by the inner heat conduction body fully around the heating space. One or both of the heat storage body and the inner heat conduction body may surround the heating space over a full circumference of the heating space. One or more of the heat storage body and the inner heat conduction body may surround the heating space over at least 50 percent, or at least 60 percent, or at least 70 percent, or at least 80 percent, or at least 90 percent of a full circumference of the heating space. One or more of the heat storage body and the inner heat conduction body may surround the heating space over no more than 90 percent, or no more than 80 percent, or no more than 70 percent, or no more than 60 percent, or no more than 50 percent of a full circumference of the heating space.
The inner heat conduction body may comprise a protrusion extending into the heating space. The protrusion may be configured to immerse into the aerosol-generating article upon insertion of the aerosol-generating article into the heating space. In particular, the protrusion may be configured to immerse into an aerosol-generating section of the aerosol-generating article. The protrusion may conduct heat into the aerosol-generating article to heat the aerosol-generating article from the inside. The protrusion may facilitate homogenous heating of the aerosol-generating article. The protrusion may have the form of a pin or a blade, for example. The protrusion may be an integral part of the inner heat conduction body. The protrusion may extend into the heating space along the axial direction. The protrusion may have a length into the axial direction between 5 and 50 millimeters, or between 5 and 40 millimeters, or between 5 and 30 millimeters, or between 5 and 25 millimeters, or between 5 and 20 millimeters, or between 5 and 15 millimeters, or between 5 and 10 millimeters, or between 2 and 5 millimeters, or between 10 and 15 millimeters, or between 10 and 20 millimeters.
The inner heat conduction body may form at least a part of a wall defining the heating space. A surface of the inner heat conduction body may at least partially delimit the heating space. If there are no elements of the aerosol-generating device between the inner heat conduction body and the aerosol-generating article received within the heating space, the inner heat conduction body may efficiently provide heat to the heating space.
The inner heat conduction body may be in contact with the heat storage body. Contact between the inner heat conduction body and the heat storage body may facilitate efficient heat transfer between the heat storage body and the inner heat conduction body. The inner heat conduction body may be in contact with the heat storage body circumferentially around the heating space.
The aerosol-generating device may comprise an outer heat conduction body. The outer heat conduction body may be provided between the heat receiving surface and the heat storage body. The outer heat conduction body may facilitate transfer of heat from the heat receiving surface to the heat storage body.
A material of the outer heat conduction body may have a higher thermal conductivity than the material of the heat storage body.
The material of the heat storage body may have a higher specific heat capacity than the material of the outer heat conduction body.
The outer heat conduction body may be formed of the same material as the inner heat conduction body.
The specific heat capacity of the material of the heat storage body may be at least 300 percent, or at least 250 percent, or at least 200 percent, or at least 150 percent, or at least 130 percent, or at least 110 percent of at least one of the specific heat capacity of the material of the inner heat conduction body and the specific heat capacity of the material of the outer heat conduction body.
At least one of the thermal conductivity of the material of the inner heat conduction body and the thermal conductivity of the material of the outer heat conduction body may be at least 500 times, or at least 400 times, or at least 300 times, or at least 200 times, or at least 100 times, or at least 50 times, or at least 30 times, or at least 10 times, or at least 5 times the thermal conductivity of the material of the heat storage body. At least one of the thermal conductivity of the material of the inner heat conduction body and the thermal conductivity of the material of the outer heat conduction body may be at least 200 percent, or at least 150 percent, or at least 130 percent, or at least 110 percent of the thermal conductivity of the material of the heat storage body.
The outer heat conduction body may be in contact with the heat storage body to facilitate heat transfer between the outer heat conduction body and the heat storage body.
The heat receiving surface may be a surface of the outer heat conduction body. The heat receiving surface may be an outer surface of the outer heat conduction body with respect to the heating space. The heat receiving surface may be a radially outer surface of the outer heat conduction body. The heat receiving surface may be a surface of the outer heat conduction body that is spaced from the heating space with respect to the axial direction.
The outer heat conduction body may circumferentially surround the heating space. The outer heat conduction body may circumferentially surround the heat storage body. The outer heat conduction body may at least partially be provided radially outwards of the heat storage body. The outer heat conduction body may at least partially be provided at a side of the heat storage body that axially faces away from the heating space.
A thermal resistance for heat transport through the outer heat conduction body in a radial direction may be different at at least two different locations of the outer heat conduction body. For example, the thermal resistance for heat transport through the outer heat conduction body at a first location of the outer heat conduction body may be at least 300 percent, or at least 250 percent, or at least 200 percent, or at least 150 percent, or at least 130 percent, or at least 110 percent of the thermal resistance for heat transport through the outer heat conduction body at a second location of the outer heat conduction body. The thermal resistance for heat transport through the outer heat conduction body in a radial direction may vary along at least one of the axial direction and a circumferential direction. A non-homogenous thermal resistance for heat transport through the outer heat conduction body in a radial direction may allow directed heat transport through the outer heat conduction body.
A thickness of the outer heat conduction body may be different at at least two different locations of the outer heat conduction body. For example, the thickness of the outer heat conduction body at a first location of the outer heat conduction body may be at least 300 percent, or at least 250 percent, or at least 200 percent, or at least 150 percent, or at least 130 percent, or at least 110 percent of the thickness of the outer heat conduction body at a second location of the outer heat conduction body. A varying thickness of the outer heat conduction body may lead to different thermal resistances for heat transport through the outer heat conduction body in a radial direction. The thickness of the outer heat conduction body may vary along at least one of the axial direction and a circumferential direction. A thickness of the outer heat conduction body may be highest at the heat receiving surface. A thickness of the outer heat conduction body may decrease with the distance to the heat receiving surface along at least one of the axial direction and the circumferential direction.
One or more channels may be provided in the outer heat conduction body. The one or more channels may influence thermal resistance for heat transport through the outer heat conduction body. Heated air may flow through the one or more channels. The one or more channels may comprise one or more openings. The one or more openings may be provided at the heat receiving surface.
A thermal resistance for heat transport through the outer heat conduction body along a radial direction may be highest at the heat receiving surface. This may prevent excessive heating of the heating chamber and the aerosol-generating article provided in the heating chamber at a position that corresponds to the position of the heat receiving surface. A high thermal resistance for heat transport through the outer heat conduction body along the radial direction at the receiving surface may cause heat from the heat receiving surface to be more evenly distributed over the heating space. The thermal resistance for heat transport through the outer heat conduction body along the radial direction may increase with the distance to heat receiving surface, in particular along at least one of the axial direction and the circumferential direction.
The outer heat conduction body may comprise two or more different materials having different thermal conductivities. The two or more different materials may be arranged to provide a desired heat conduction profile. The two or more different materials may be arranged to provide a desired distribution of a thermal resistance for heat transport through the outer heat conduction body along a radial direction. The outer heat conduction body may, for example, comprise two or more layers, wherein each layer is formed of a different material. The layers may, for example, be arranged one behind the other with respect to the axial direction or with respect to a radial direction (or both the axial direction and the radial direction).
The aerosol-generating device may further comprise a heater configured to heat the heat receiving surface. The heater may, for example, comprise an electrical resistance heater, or an induction heater. The heater may be configured to generate one or more flames to heat the heat receiving surface. The heater may be configured to burn gas to generate the one or more flames. The one or more flames may comprise at least two flames. The heater may be formed integrally with a main body of the aerosol-generating device. Alternatively, the heater may be, fully or partially, provided as a separate entity. The heater may, for example, be a conventional cigarette lighter.
According to a further aspect of the present invention, there is provided an aerosol-generating system. The aerosol-generating system may comprise the aerosol-generating device and the aerosol-generating article. The aerosol-generating article may have an aerosol-generating section. The aerosol-generating section may comprise material configured to generate aerosol upon being heated. The aerosol-generating section may be at least partially received in the heating space when the aerosol-generating article is at least partially received in the heating space.
According to another aspect of the present invention, there is provided a method for generating aerosol. The method comprises heating a heat receiving surface of an aerosol-generating device. The aerosol-generating device at least partially receives an aerosol-generating article. Heat from heating the heat receiving surface is stored in a heat storage body provided between the heat receiving surface and the aerosol-generating article. Heat is distributed to the aerosol-generating article via an inner heat conduction body provided between the heat storage body and the aerosol-generating article. A material of the heat storage body has a higher specific heat capacity than a material of the inner heat conduction body.
The material of the inner heat conduction body may have a higher thermal conductivity than the material of the heat storage body.
The heat receiving surface may be heated with more than one flame at the same time. For example, the heat receiving surface may be heated with two or more than two flames at the same time. Heating the heat receiving surface with more than one flame at the same time allows using smaller flames to convey a specific amount of heat to the heat receiving surface as compared to using only one flame. Further, using more than one flame at the same time allows spatially distributing the heat in an efficient manner.
The aerosol-generating article may extend along an axial direction when the aerosol-generating article is at least partially received in the aerosol-generating device. The axial direction may correspond to a direction along which the aerosol-generating article is inserted into the aerosol-generating device.
At least two of the flames may be generated at different circumferential positions around the axial direction. Heat may thus be supplied from different circumferential angles around the axial direction.
At least two of the flames may be spaced along a direction parallel to the axial direction. Heat may thus be supplied at different positions along the axial direction.
According to another aspect of the present invention, there is provided a method for generating aerosol. The method comprises heating a heat receiving surface of an aerosol-generating device. The aerosol-generating device at least partially receives an aerosol-generating article extending along an axial direction. The heat receiving surface is heated with more than one flame at the same time.
At least two of the flames may be generated at different circumferential positions around the axial direction.
At least two of the flames may be spaced along a direction parallel to the axial direction.
According to a further aspect of the present invention, there is provided a use of an axially extending tube that circumferentially surrounds an aerosol-generating substance to achieve substantially homogeneous heating of the aerosol-generating substance, wherein a thermal resistance for heat transport through the tube along a radial direction varies along at least one of the axial direction and a circumference of the tube.
For example, the thermal resistance for heat transport through the tube along a radial direction may vary along at least one of the axial direction and a circumference of the tube by at least 200 percent, or by at least 150 percent, or by at least 100 percent, or by at least 70 percent, or by at least 50 percent, or by at least 30 percent, or by at least 20 percent, or by at least 10 percent of a minimum value of the thermal resistance for heat transport through the tube along a radial direction.
The thermal resistance for heat transport through the tube along a radial direction may change along at least one of the axial direction and the circumference of the tube in a way that influences heat transport towards the aerosol-generating substance to be substantially homogeneous. For example, a thermal resistance for heat transport through the tube along a radial direction may be highest at a location that is nearest to a heat source. The thermal resistance may decrease from that location along at least one of the axial direction and the circumference of the tube.
Substantially homogenous heating of the aerosol-generating substance may be achieved if during heating, a temperature difference of two portions of the aerosol-generating substance is not higher than 100 degrees Celsius, or not higher than 75 degrees Celsius, or not higher than 50 degrees Celsius, or not higher than 25 degrees Celsius, or not higher than 10 degrees Celsius. The aerosol-generating article referred to herein may be at least essentially rod-shaped.
The aerosol-generating article may extend in parallel to the axial direction, when at least partially inserted into the aerosol-generating device.
The aerosol-generating article may comprise an aerosol-generating section. The aerosol-generating section may comprise aerosol-generating material. The aerosol-generating material may be configured to release aerosol upon being heated. The aerosol-generating material may, for example, comprise herbaceous material. The aerosol-generating material may, for example, comprise tobacco material.
The aerosol-generating article may comprise a filter section. When the aerosol-generating article is inserted into the aerosol-generating device, the filter section may at least partially protrude from the aerosol-generating device to be accessible to a user.
According to a further aspect of the present invention there is provided an aerosol-generating system comprising an aerosol-generating device according to any one of the embodiments, aspects, or examples described herein. The aerosol-generating system also comprises the aerosol-generating article. The aerosol-generating article may comprise an aerosol-forming substrate which may be the aerosol-generating material. As used herein, the term “aerosol-generating article” refers to an article comprising an aerosol-forming substrate that, when heated, releases volatile compounds that can form an aerosol.
The aerosol-forming substrate may comprise a plug of tobacco. The tobacco plug may comprise one or more of: powder, granules, pellets, shreds, spaghettis, strips or sheets containing one or more of: tobacco leaf, fragments of tobacco ribs, reconstituted tobacco, homogenised tobacco, extruded tobacco and expanded tobacco. Optionally, the tobacco plug may contain additional tobacco or non-tobacco volatile flavour compounds, to be released upon heating of the tobacco plug. Optionally, the tobacco plug may also contain capsules that, for example, include the additional tobacco or non-tobacco volatile flavour compounds. Such capsules may melt during heating of the tobacco plug. Alternatively, or in addition, such capsules may be crushed prior to, during, or after heating of the tobacco plug.
Where the tobacco plug comprises homogenised tobacco material, the homogenised tobacco material may be formed by agglomerating particulate tobacco. The homogenised tobacco material may be in the form of a sheet. The homogenised tobacco material may have an aerosol-former content of greater than 5 percent on a dry weight basis. The homogenised tobacco material may alternatively have an aerosol former content of between 5 percent and 30 percent by weight on a dry weight basis. Sheets of homogenised tobacco material may be formed by agglomerating particulate tobacco obtained by grinding or otherwise comminuting one or both of tobacco leaf lamina and tobacco leaf stems; alternatively, or in addition, sheets of homogenised tobacco material may comprise one or more of tobacco dust, tobacco fines and other particulate tobacco by-products formed during, for example, the treating, handling and shipping of tobacco. Sheets of homogenised tobacco material may comprise one or more intrinsic binders, that is tobacco endogenous binders, one or more extrinsic binders, that is tobacco exogenous binders, or a combination thereof to help agglomerate the particulate tobacco. Alternatively, or in addition, sheets of homogenised tobacco material may comprise other additives including, but not limited to, tobacco and non-tobacco fibres, aerosol-formers, humectants, plasticisers, flavourants, fillers, aqueous and non-aqueous solvents and combinations thereof. Sheets of homogenised tobacco material are preferably formed by a casting process of the type generally comprising casting a slurry comprising particulate tobacco and one or more binders onto a conveyor belt or other support surface, drying the cast slurry to form a sheet of homogenised tobacco material and removing the sheet of homogenised tobacco material from the support surface.
The aerosol-generating article may have a total length of between approximately 30 millimetres and approximately 100 millimetres. The aerosol-generating article may have an external diameter of between approximately 5 millimetres and approximately 13 millimetres.
The aerosol-generating article may comprise a mouthpiece positioned downstream of the tobacco plug. The mouthpiece may be located at a downstream end of the aerosol-generating article. The mouthpiece may be a cellulose acetate filter plug. Preferably, the mouthpiece is approximately 7 millimetres in length, but can have a length of between approximately 5 millimetres to approximately 10 millimetres.
The tobacco plug may have a length of approximately 10 millimetres. The tobacco plug may have a length of approximately 12 millimetres.
The diameter of the tobacco plug may be between approximately 5 millimetres and approximately 12 millimetres.
In a preferred embodiment, the aerosol-generating article has a total length of between approximately 40 millimetres and approximately 50 millimetres. Preferably, the aerosol-generating article has a total length of approximately 45 millimetres. Preferably, the aerosol-generating article has an external diameter of approximately 7.2 millimetres.
The present disclosure comprise various aspects, embodiments, and examples. Features, advantages, and explanations disclosed with reference to any one of those aspects, embodiments, and examples may be combined with, or transferred to, any one of the remaining aspects, embodiments, and examples. The aerosol-generating devices or systems described herein may be suitable, adapted and configured to carry out the methods for generating aerosol described herein.
Where the present disclosure refers to a material of an item having a certain specific heat capacity and the item is comprised of different individual materials (for example different material layers), the specific heat capacity of the material of the item is to be understood as corresponding to a weighted average of the specific heat capacities of the individual materials of which the item is comprised. The weighting is understood to be carried out according to the mass percentages of the individual materials of which the item is comprised.
Where the present disclosure refers to a material of an item having a certain thermal conductivity and the item is comprised of different individual materials (for example different material layers), the thermal conductivity of the material of the item is to be understood as corresponding to a weighted average of the thermal conductivities of the individual materials of which the item is comprised. The weighting is understood to be carried out according to the mass percentages of the individual materials of which the item is comprised.
The expression “rod-shaped” as used herein includes, but is not limited to, rod-shapes with a circular cross-section. “Rod-shaped” as used herein may also include rod-shapes with other cross-sections, such as, for example, a rectangular cross-section, or an elliptic cross-section, or a triangular cross-section, or an irregular cross-section, or any other cross-section. The expression “rod-shaped” may include cylindrical shapes, whereby the base surface of the cylinder may be a circular surface or a surface of any other shape, such as a rectangular surface, or an elliptic surface, or a triangular surface, or an irregular surface, or any other surface.
When a first item immerses into a second item, the first item may at least partially enter a volume of the second item. After immersing into the second item, at least a part of the first item may be surrounded by the second item. For example, a first item may immerse into a second item by being pushed into the second item.
The invention is defined in the claims. However, below there is provided a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of another example, embodiment, or aspect described herein.
Embodiments will now be further described with reference to the figures, in which:
As shown in
In the embodiment of
The heater 7 is configured to heat a heat receiving surface 25 of the heating chamber 15. By heating the heat receiving surface 25, the heating space 21 within the heating chamber 15 is heated, thereby heating the aerosol-generating section 9 of the aerosol-generating article 3. When heated, the aerosol-generating section 9 generates aerosol. When a user draws air through the filter section 13, an airflow through the aerosol-generating article 5 (see arrows in
In the embodiment of
In
A material of the heat storage body 31 has a higher specific heat capacity than a material of the inner heat conduction body 33 and a material of the outer heat conduction body 29. The material of the outer heat conduction body 29 and the material of the inner heat conduction body 33 have higher thermal conductivities than the material of the heat storage body 31. The material of the heat storage body 31 may, for example, be glass or metal. One or both of the material of the inner heat conduction body 33 and the material of the outer heat conduction body 29 may be a metal, such as copper, brass or aluminum, for example.
When the heat receiving surface 25 is heated, the heat is efficiently guided radially inside towards the heat storage body 31 by the outer heat conduction body 29. The heat storage body 31, due to its high specific heat capacity, may serve as a buffer taking up comparatively large amounts of heat and giving the heat up over time to heat the heating space 21 and the aerosol-generating section 9 provided therein. The inner heat conduction body 33 forms an inner surface of the heating chamber 15 defining the heating space 21. The inner heat conduction body 33 efficiently conducts heat from the heat storage body 31 towards the heating space 21 and the aerosol-generating section 9 provided therein.
In
In
Due to the different thickness of the outer heat conduction body 29 at different locations, a thermal resistance for heat transport through the outer heat conduction body 29, and thus through the walls of the heating chamber 15, along a radial direction is different for different locations. Due to the highest thickness of the outer heat conduction body 29 at the heat receiving surface 25, in particular at the center of the heat receiving surface 25, the thermal resistance for heat transport through the outer heat conduction layer 29 along the radial direction is highest at the heat receiving surface 25. This may counteract an inhomogeneous temperature distribution within the heating space 21 by having a reduced thermal resistance for heat transport at locations that are farther away from the heat receiving surface 25 and would therefore normally receive less heat.
In
Between the heat storage body 31 and the heating space 21, an inner heat conduction body 33 is provided. The inner heat conduction body 33 comprises a plate extending essentially perpendicular to the axial direction between the heat storage body 31 and the heating space 21. Further, the inner heat conduction body 33 comprises a cylindrical sleeve part 37 circumferentially surrounding the heating space 21. Further, the inner heat conduction body 33 comprises a protrusion 39 extending into the heating space 21. The protrusion 39 is configured to immerse into the aerosol-generating section 9 of the aerosol-generating article 5.
In the embodiment of
The heater 7 of the system 1 of
For the purpose of the present description and of the appended claims, except where otherwise indicated, all numbers expressing amounts, quantities, percentages, and so forth, are to be understood as being modified in all instances by the term “about”. Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein. In this context, therefore, a number A is understood as A±5 percent of A. Within this context, a number A may be considered to include numerical values that are within general standard error for the measurement of the property that the number A modifies. The number A, in some instances as used in the appended claims, may deviate by the percentages enumerated above provided that the amount by which A deviates does not materially affect the basic and novel characteristic(s) of the claimed invention. Also, all ranges include the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein.
| Number | Date | Country | Kind |
|---|---|---|---|
| 21167592.1 | Apr 2021 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/059484 | 4/8/2022 | WO |
