EA043642B1 - DEVICE GENERATING AEROSOL AND HEATING CHAMBER FOR IT - Google Patents

Abstract

The aerosol generating device (100) has a heating chamber (108) for receiving a substrate holder (114) containing an aerosol forming substrate (128). The heating chamber (108) comprises a tubular side wall having an open first end; and a flange portion at the open first end of the tubular wall, wherein the flange portion extends outwardly from the tubular side wall. The flange portion (138) is held between a first washer (107a) and a second washer (107b).

Description

Field of technology

The invention relates to a device that generates an aerosol and a heating chamber for it. The invention is particularly applicable to a portable aerosol generating device which may be self-contained and low temperature. Such devices may heat, rather than burn, tobacco or other suitable materials by conduction, convection and/or radiation to generate an inhalable aerosol.

Prerequisites for creating the invention

The popularity and use of reduced-risk or modified-risk devices (also known as vaporizers) have grown rapidly in the past few years as a way to help seasoned smokers want to quit smoking traditional tobacco products such as cigarettes, cigars, cigarillos and roll-your-own tobacco. Various devices and systems are available that heat or preheat substances capable of forming an aerosol, as opposed to combustion of tobacco in conventional tobacco products.

A generally available reduced risk or modified risk device is a heated device that generates an aerosol from a substrate or a non-combustion heating device. Devices of this type generate an aerosol or vapor by heating an aerosol-forming substrate, typically containing moistened leaf tobacco or other suitable aerosol-forming material, to a temperature typically in the range of 150 to 300°C. When the aerosol-forming substrate is heated, but not combusted or burned, an aerosol is released containing components desired by the user, but not the toxic and carcinogenic byproducts of combustion and combustion. In addition, an aerosol produced by heating tobacco or other material capable of forming an aerosol does not typically produce a burnt or bitter taste due to combustion or combustion that may be unpalatable to the user, and therefore does not require sugars or other additives in the substrate, which are usually added to such materials in order to make the taste of smoke and/or vapor more attractive to the user.

In general terms, it is required to rapidly heat the aerosol-forming substrate to a temperature at which it can release an aerosol, and to maintain the aerosol-forming substrate at that temperature. It will be appreciated that the aerosol will be released from the aerosol-forming substrate and delivered to the user only when a stream of air passes through the aerosol-forming substrate.

This type of aerosol generating device is a portable device, so power consumption is an important design consideration. The present invention is directed to solving problems existing in existing devices and to providing an improved aerosol generating device and heating chamber therefor.

The essence of the invention

According to a first aspect of the invention, there is provided a heating chamber for an aerosol generating device, the heating chamber comprising: a tubular side wall having an open first end; and a flange portion at the open first end of the tubular wall, the flange portion extending outwardly from the tubular side wall; the flange portion being held between the first washer and the second washer.

Optionally, the first and second washers are formed from a thermal insulating material, wherein preferably the thermal insulating material is polyetheretherketone (PEEK).

Optionally, the heating chamber extends through the central opening of the second washer.

Optionally, the flange portion is located in a recess in the first washer or the second washer.

Optionally, the flange portion extends completely around the heating chamber.

Optionally, the flange portion extends obliquely from the tubular sidewall.

Optionally, the tubular sidewall has a thickness of 90 microns or less.

Optionally, the heating chamber further has a base attached to the tubular side wall at a second end opposite the first end.

Optionally, the tubular sidewall and flange portion comprise metal, wherein preferably the metal is stainless steel, even more preferably the metal is 300 grade stainless steel, even more preferably the metal is selected as one of 304 grade stainless steel, 316 grade stainless steel, and 321 grade steel.

Optionally, the heating chamber contains a material having a thermal conductivity of 50 W/m-K or less.

Optionally, the flange portion contains a first material and the side wall contains a second material, wherein the first material has a lower thermal conductivity than the second material.

Optionally, the heating chamber is at least partially manufactured by deep drawing.

The present invention also discloses an aerosol generating device comprising: a power supply; the heating chamber described above; a heater configured to supply heat to the heating chamber; and a control circuit configured to

- 1 043642 control the power supply from the power supply to the heater.

Optionally, the heating chamber is attached to the aerosol generating device by a flange portion, preferably the flange portion being located between two portions of the device for attaching the heating chamber to the device.

Optionally, the heater is provided on the outer surface of the side wall.

Optionally, the heater is located adjacent to the outer surface of the side wall.

Optionally, the heating chamber is removable from the aerosol generating device for heating without combustion.

Optionally, the aerosol generating device further comprises an outer shell housing a power source, a heating chamber, a heater, and a control circuit, the heating chamber being held at a distance from an interior surface of the outer shell by a first washer and a second washer (sometimes referred to as a pair of washers). In other words, the heating chamber is suspended by the heating chamber flange, held between a pair of washers.

Optionally, the heating chamber further comprises thermal insulation surrounding the heating chamber. Consequently, the heating chamber is further kept at a distance from the thermal insulation.

Optionally, the outer shell is folded or curved around the top of the washers at the second end of the aerosol generating device to hold the washers in place. Optionally, the second of the washers (ie the washer furthest from the second end of the aerosol generating device) rests on the shoulder or annular ridge of the outer shell.

Brief description of graphic materials

In fig. 1 is a schematic perspective view of an aerosol generating device according to a first embodiment of the present invention.

In fig. 2 is a schematic side sectional view of the aerosol generating device of FIG. 1.

In fig. 2(a) is a schematic cross-sectional top view of the aerosol generating device of FIG. 1 along line X-X shown in FIG. 2.

In fig. 3 is a schematic perspective view of the aerosol generating device of FIG. 1, shown with an aerosol-generating substrate holder loaded into the aerosol-generating device.

In fig. 4 is a schematic side sectional view of the aerosol generating device of FIG. 1, shown with an aerosol-generating substrate holder loaded into the aerosol-generating device.

In fig. 5 is a schematic perspective view of the aerosol generating device of FIG. 1, shown with an aerosol-generating substrate holder loaded into the aerosol-generating device.

In fig. 6 is a schematic side sectional view of the aerosol generating device of FIG. 1, shown with an aerosol-generating substrate holder loaded into the aerosol-generating device.

In fig. 6(a) is a detailed sectional view of a portion of FIG. 6, which highlights the interaction between the substrate holder and the projections in the heating chamber and the corresponding effect on air flow paths.

In fig. 7 is a top view of the heater separated from the heating chamber.

In fig. 8 is a schematic side sectional view of an aerosol generating device according to a second embodiment of the present invention having an alternative air flow configuration.

In fig. 9 is a schematic side sectional view of a heating chamber according to a third embodiment of the invention having a heating chamber with a flange that is thicker than the side wall.

In fig. 9(a) is a top perspective view of a heating chamber of an aerosol generating device according to a third embodiment of the present invention.

In fig. 9(b) is a bottom perspective view of a heating chamber of an aerosol generating device according to a third embodiment of the present invention.

In fig. 10 is a schematic perspective view of a heating chamber according to a fourth embodiment of the invention having a heating chamber with an inclined flange.

In fig. 10(a) is a top perspective view of a heating chamber of an aerosol generating device according to a fourth embodiment of the present invention.

In fig. 10(b) is a bottom perspective view of a heating chamber of an aerosol generating device according to a fourth embodiment of the present invention.

In fig. 11 is a schematic perspective view of a heating chamber according to a fifth embodiment of the invention having a heating chamber with a flange formed as a separate member.

- 2 043642

In fig. 11(a) is a top perspective view of a heating chamber of an aerosol generating device according to a fifth embodiment of the present invention.

In fig. 11(b) is a bottom perspective view of a heating chamber of an aerosol generating device according to a fifth embodiment of the present invention.

In fig. 12 is a schematic side sectional view of an aerosol generating device according to a sixth embodiment of the invention having a heating chamber with a flange that is located in a recess in the mounting washers.

In fig. 13 is a schematic side sectional view of an aerosol generating apparatus according to a seventh embodiment of the invention having a heating chamber with an inclined flange which is located in a recess in the mounting washers.

Detailed Description of Embodiments

First embodiment.

With reference to FIG. 1 and 2, according to a first embodiment of the present invention, the aerosol generating device 100 includes an outer shell 102 housing various components of the aerosol generating device 100. In the first embodiment, the outer shell 102 is tubular. More specifically, it is cylindrical. It should be noted that the outer shell 102 need not be tubular or cylindrical in shape, but can be any shape as long as it is sized to accommodate the components described in the various embodiments set forth herein. The outer shell 102 may be formed from any suitable material or, furthermore, from layers of material. For example, an inner layer of metal may be surrounded by an outer layer of plastic. This provides a pleasant feeling to the user when holding the outer shell 102. Any heat leakage from the aerosol generating device 100 is distributed around the circumference of the outer shell 102 by the metal layer, thereby preventing the formation of hot spots, while the plastic layer softens the outer shell 102 to the touch. In addition, the plastic layer may help protect the metal layer from oxidation or scratching, which improves the appearance of the aerosol generating device 100 in the long term.

The first end 104 of the aerosol generating device 100, shown toward the bottom of each of FIGS. 1-6 is, for convenience, described as the bottom, base, or lower end of the aerosol generating device 100. The second end 106 of the aerosol generating device 100, shown toward the top of each of FIGS. 1-6 is described as the top or upper end of the aerosol generating device 100. In the first embodiment, the first end 104 is the lower end of the outer shell 102. In use, the user typically orients the aerosol generating device 100 with the first end 104 downward and/or distal to the user's mouth and the second end 106 upward and/or proximal. position relative to the user's mouth.

As shown, the aerosol generating device 100 holds in place a pair of washers 107a, 107b at the second end 106 by an interference fit with the interior of the outer shell 102 (only the top washer 107a is visible in FIGS. 1, 3 and 5). In some embodiments, the outer shell 102 is folded or curved around the top of the washers 107a at the second end 106 of the aerosol generating device 100 to hold the washers 107a, 107b in place. The second of the washers 107b (i.e., the washer furthest from the second end 106 of the aerosol generating device 100) rests on the shoulder or annular ridge 109 of the outer shell 102, thereby preventing the lower washer 107b from seating more than a predetermined distance from the second end 106 aerosol generating device 100. The washers 107a, 107b are formed from a heat insulating material. In this embodiment, the thermal insulating material is suitable for use in medical devices, such as polyetheretherketone (PEEK).

The aerosol generating device 100 has a heating chamber 108 disposed toward the second end 106 of the aerosol generating device 100. The heating chamber 108 is open towards the second end 106 of the aerosol generating device 100. The aerosol generating device 108 has a first open end 110 towards the second end 106 of the aerosol generating device 100. The heating chamber 108 is held away from the inner surface of the outer shell 102 by passing through the central opening of the bottom washer 107b. In this arrangement, the heating chamber 108 is held broadly coaxial with the outer shell 102. The heating chamber 108 is suspended by a heating chamber 108 flange 138 located at the open end 110 of the heating chamber 108 and held between a pair of washers 107a, 107b. This means that heat conduction from the heating chamber 108 to the outer shell 102 typically passes through the washers 107a, 107b and is thus limited by the insulating properties of the washers 107a, 107b. Since there is an air gap otherwise surrounding the heating chamber 108, heat transfer from the heating chamber 108 to the outer shell 102 other than through the washers 107a, 107b is also reduced. In the illustrated embodiment, flange 138 extends outward from side wall 126 of heating chamber 108 to

- 3 043642 distance of approximately 1 mm, forming a ring structure.

To further enhance the thermal insulation of heating chamber 108, heating chamber 108 is also surrounded by insulation. In some embodiments, the insulation is a fibrous material or foam material, such as cotton wool. In the illustrated embodiment, the insulation includes an insulating element 152 in the form of an insulating sleeve containing a double-wall tube 154 and a base 156. In some embodiments, the insulating element 152 may include a pair of nested sleeves enclosing a cavity therebetween. The cavity 158 formed between the walls of the double-wall tube 154 may be filled with thermally insulating material, such as fibers, foams, gels, or gases (eg, low pressure). In some cases, cavity 158 may contain a vacuum. Advantageously, a vacuum requires very little thickness to achieve high thermal insulation, and the walls of the double-wall tube 154 enclosing the cavity 158 can be up to 100 microns thick, and the total thickness (of the two walls and the cavity 158 between them) can be up to 1 mm. The base 156 is an insulating material such as silicone. Because silicone is malleable, electrical connections 150 to heater 124 may pass through base 156 forming a seal around electrical connections 150.

As shown in FIG. 1-6, aerosol generating device 100 may include an outer shell 102, a heating chamber 108, and an insulating element 152, as described in detail above. In fig. 1-6 illustrate a resilient member 160 positioned between the outwardly facing surface of the insulating sidewall 154 and the interior surface of the outer shell 102 to hold the insulating member 152 in place. Resilient member 160 may provide sufficient friction to provide an interference fit to hold insulating member 152 in place. Resilient member 160 may be a gasket or O-ring or other closed loop of material that conforms to the shape of the outward facing surface of the insulating side wall 154 and the inner surface of the outer shell 102. The elastically deformable element 160 may be formed from a thermally insulating material such as silicone. This may provide additional insulation between the insulating member 152 and the outer shell 102. In this way, heat transfer to the outer shell 102 can be reduced so that the user can comfortably hold the outer shell 102 during use. The elastically deformable material is designed to compress and deform, but springs back back to its previous form, and represents, for example, elastic or rubber materials.

As an alternative to this arrangement, the insulating element 152 may be supported by supports extending between the insulating element 152 and the outer shell 102. The supports provide increased rigidity so that the heating chamber 108 is centrally located in the outer shell 102, or so that it is located at a given location. This can be designed so that the heat is evenly distributed throughout the entire outer shell 102 in order to avoid the development of hot spots.

As yet another alternative, the heating chamber 108 may be secured to the aerosol generating device 100 by engaging portions on the outer shell 102 to engage the side wall 126 at the open end 110 of the heating chamber 108. Since the open end 110 is exposed to greatest flow of cold air and therefore cools fastest, attaching the heating chamber 108 to the outer shell 102 adjacent the open end 110 may allow heat to quickly dissipate into the environment and provide a secure fit.

It should be noted that in some embodiments, the heating chamber 108 is removable from the aerosol generating device 100. Thus, the heating chamber 108 can be easily cleaned or replaced. In such embodiments, the heater 124 and electrical connections 150 may be non-removable and may remain in place within the insulating member 152.

In the first embodiment, the base 112 of the heating chamber 108 is closed. That is, the heating chamber 108 is shaped like a sleeve. In other embodiments, the base 112 of the heating chamber 108 has one or more openings or is perforated, with the heating chamber 108 remaining generally in the form of a sleeve but not closed to the base 112. In other embodiments, the base 112 is closed, but the side wall 126 has one or more holes or is perforated in an area adjacent to base 112, such as between heater 124 (or metal layer 144) and base 112. Heating chamber 108 also has a side wall 126 between base 112 and open end 110. Side wall 126 and base 112 are connected to each other. In the first embodiment, the side wall 126 is tubular. More specifically, it is cylindrical. However, in other embodiments, the side wall 126 has other suitable shapes, such as a tube shape with an elliptical or polygonal cross-section. Usually the cross section is uniform

- 4 043642 along the length of the heating chamber 108 (ignoring the projections 140), however in other embodiments it may vary, for example the cross-section may decrease in size towards one end so that the tubular shape is tapered or frusto-conical.

In the illustrated embodiment, heating chamber 108 is one-piece, that is, side wall 126 and base 112 are formed from a single piece of material, such as by a deep drawing process. This may result in an overall stronger heating chamber 108. Other examples may have a base 112 and/or a flange 138 formed as a separate piece and then attached to the side wall 126. This in turn allows the flange 138 and/or to be formed or a base 112 made of a material different from the material from which the side wall 126 is made. The side wall 126 itself is made of thin wall. In some embodiments, the side wall has a thickness of up to 150 microns. Typically, the side wall 126 has a thickness of less than 100 microns, such as about 90 or even about 80 microns. In other cases, it is possible for the side wall 126 to have a thickness of approximately 50 microns, although as the thickness decreases, the failure rate during the process increases. In general, a range of 50 to 100 µm is usually suitable, with a range of 70 to 90 µm being optimal. Manufacturing tolerances are approximately ±10 µm, but specified parameters must be accurate to approximately ±5 µm.

If the side wall 126 is as thin as described above, the thermal properties of the heating chamber 108 change markedly. Heat transfer through the side wall 126 experiences negligible resistance because the side wall 126 is so thin that heat transfer along the side wall 126 (i.e., parallel to the central axis or circumference of the side wall 126) has a small channel along which conduction can occur, and thus the heat generated by the heater 124 located on the outer surface of the heating chamber 108 remains localized in the vicinity of the heater 124 in a direction radially outward from the side wall 126 at the open end, but quickly causes the interior surface of the heating chamber 108 to heat up. In addition, the thin side wall 126 helps reduce the heat capacity of the heating chamber 108, which in turn increases the overall efficiency of the aerosol generating device 100 since less energy is used when heating the side wall 126.

The heating chamber 108 and, in particular, the side wall 126 of the heating chamber 108 contains a material having a thermal conductivity of 50 W/m-K or less. In the first embodiment, heating chamber 108 is metal, preferably stainless steel. Stainless steel has a thermal conductivity of approximately 15 to 40 W/m-K, with the exact value depending on the specific alloy. As a further example, 300 grade stainless steel, which is suitable for this application, has a thermal conductivity of approximately 16 W/m-K. Suitable examples include 304, 316, and 321 stainless steel, which have been approved for medical use, are durable, and have low enough thermal conductivity to provide the heat containment capabilities described in the present invention.

Materials with thermal conductivity at the levels described reduce the ability to conduct heat away from the area to which heat is applied, compared to materials with higher thermal conductivity. For example, the heat remains localized adjacent to the heater 124. Since the movement of heat to other parts of the aerosol generating device 100 is suppressed, heating efficiency is thus increased by ensuring that only those parts of the aerosol generating device 100 that are intended to be heated actually heat up. for heating, and those that are not intended do not heat up.

Metals are suitable materials because they are strong, malleable, and easy to shape and form. In addition, their thermal properties vary widely from metal to metal and can be adjusted if necessary by careful selection of the alloy composition. In this invention, “metal” refers to elemental (ie, pure) metals, as well as alloys of several metals or other elements, such as carbon.

Accordingly, the configuration of the heating chamber 108 with thin side walls 126, together with the selection of materials with desired thermal properties from which the side walls 126 are formed, allows heat to be efficiently conducted through the side walls 126 and into the aerosol-forming substrate 128. This also advantageously results in a reduction in the time required to raise the temperature from ambient temperature to the temperature at which aerosol can be released from aerosol-forming substrate 128 after initial actuation of the heater.

The heating chamber 108 is formed by deep drawing. It is an effective way to form the heating chamber 108 and can be used to provide a very thin side wall 126. The deep drawing process involves pressing a sheet metal blank using a punch to press it into a die of a specific shape. By using a series of punches and dies with gradually decreasing dimensions, a tubular tube is formed

- 5 043642 a structure having a base at one end and a tube whose depth is greater than the distance across the tube (that is, the tube is relatively longer than it is wide, giving rise to the term deep draw). Due to the formation in this way, the side wall of the tube thus formed has the same thickness as the original sheet metal. Likewise, the base thus formed has the same thickness as the original sheet metal blank. A flange may be formed at the end of the tube by leaving the rim of the original sheet metal blank extending outward at the end of the tubular wall opposite the base (ie, starting with more material in the blank than is required to form the tube and base). Alternatively, the flange may be subsequently formed in a separate step involving one or more of cutting, bending, rolling, crimping, etc.

As described, the tubular side wall 126 according to the first embodiment is thinner than the base 112. This can be achieved by first deep drawing the tubular side wall 126 and then thinning the wall. The term thinning drawing refers to heating the tubular sidewall 126 and drawing it so that it becomes thinner during the process. Thus, the tubular side wall 126 can be configured to the dimensions described in the present invention.

The thin side wall 126 may be fragile. The effects of this can be reduced by providing additional structural support for the side wall 126 and by forming the side wall 126 in a tubular, and preferably cylindrical, shape. In some cases, additional structural support is provided as an optional feature, however, it should be noted that some structural support is also provided by the flange 138 and base 112. Looking primarily at the base 112, it should be noted that the tube, open at both ends, is generally more susceptible to collapse, while providing the heating chamber 108 of the present invention with a base 112 adds support. It should be noted that in the illustrated embodiment, the base 112 has a greater thickness than the side wall 126, such as 2 to 10 times the thickness of the side wall 126. In some cases, this may result in the base 112 having a thickness of 200 to 500 µm, for example a thickness of 400 µm. The base 112 also has the additional purpose of preventing the substrate holder 114 from being inserted too far into the aerosol generating device 100. The increased thickness of the base 112 helps prevent damage to the heating chamber 108 if the user inadvertently applies too much force when inserting the cartridge holder 114. Likewise, when a user cleans heating chamber 108, the user may typically insert an object, such as an elongated brush, through the open end 110 of heating chamber 108. This means that the user is more likely to apply more force to the base 112 of the heating chamber 108 because the elongated object rests against the base 112 rather than against the side wall 126. Therefore, the thickness of the base 112 relative to the side wall 126 may help prevent damage to the heating chamber 108 in during cleaning. In other embodiments, the base 112 has the same thickness as the side wall 126, which provides some of the benefits discussed above.

The flange 138 extends outward from the side wall 126 and has an annular shape extending around the entire circumference of the rim of the side wall 126 at the open end 110 of the heating chamber 108. The flange 138 resists bending and shear forces against the side wall 126. For example, lateral deformation of the tube formed by the side wall wall 126 is likely to require bending of the flange 138. It should be noted that although the flange 138 is shown to extend broadly perpendicular to the side wall 126, the flange 138 may extend obliquely relative to the side wall 126, for example, forming in conjunction with the side wall 126 funnel shape, while still maintaining the above-described advantageous features. In some embodiments, the flange 138 is not annular, but is located only partially around the rim of the side wall 126. In the illustrated embodiment, the flange 138 is the same thickness as the side wall 126, however, in other embodiments, the flange 138 is thicker to improve resistance to deformation. thickness than the side wall 126. Any increase in the thickness of a particular portion to increase its strength must be weighed against the added heat capacity increase so that the aerosol generating device 100 as a whole remains strong but effective.

A plurality of projections 140 are formed in the inner surface of the side wall 126. The width of the projections 140 around the perimeter of the side wall 126 is small relative to their length parallel to the central axis of the side wall 126 (or, more broadly, in the direction from the base 112 to the open end 110 of the heating chamber 108). . In this example, there are four protrusions 140. Four is generally a suitable number of protrusions 140 to hold the cartridge holder 114 in a central position in the heating chamber 108, as will be apparent from the following discussion. In some embodiments, three projections may be sufficient, for example, spaced (evenly) at intervals of approximately 120 degrees around the circumference of the side wall 126. The projections 140 have a variety of purposes, and the precise shape of the projections 140 (and corresponding recesses on

- 6 043642 outer surface of the side wall 126) is selected based on the required result. In either case, the projections 140 extend toward and engage the cartridge holder 114 and are therefore sometimes referred to as engagement elements. Moreover, the terms protrusion and engagement element are used interchangeably in the present invention. Likewise, if the projections 140 are provided by extrusion of the side wall 126 from the outside, such as by hydraulic molding or compression molding, etc., the term recess is also used interchangeably with the terms projection and engagement element. Forming the projections 140 by pressing the side wall 126 has the advantage that they are integral with the side wall 126 and therefore have minimal impact on heat flow. In addition, the projections 140 do not add additional heat capacity, as would be the case if an additional element was added to the inner surface of the side wall 126 of the heating chamber 108. Moreover, as a result of the formation of the projections 140 by pressing the side wall 126, the thickness of the side wall 126 remains substantially constant in the circumferential and/or axial direction even if the projections are provided. Finally, the described sidewall indentation increases the strength of the sidewall 126 by introducing portions extending transversely to the sidewall 126, thereby rendering the sidewall 126 resistant to bending.

The heating chamber 108 is configured to receive a substrate holder 114 . Typically, the substrate holder contains an aerosol-forming substrate 128, such as tobacco or other suitable aerosol-forming material, capable of being heated to generate an inhalable aerosol. In the first embodiment, the heating chamber 108 is sized to receive one portion of aerosol-forming substrate 128 in the form of a substrate holder 114, also known as a consumable, as shown in FIG. 3-6, for example. However, this is not essential, and in other embodiments, heating chamber 108 is configured to receive aerosol-forming substrate 128 in other forms, such as loose tobacco or tobacco packaged in other ways.

The aerosol generating device 100 operates both by conducting heat from the surface of the projections 140 engaging the outer layer 132 of the substrate holder 114 and by heating the air in the air gap between the inner surface of the side wall 126 and the outer surface of the substrate holder 114. That is, convective heating of the aerosol-generating substrate 128 occurs as heated air is drawn through the aerosol-generating substrate 128 when the user applies suction through the aerosol-generating device 100 (as described in more detail below). The width and height (ie, the distance that each projection 140 extends into the heating chamber 128) increases the surface area of the side wall 126 that conducts heat into the air, allowing the aerosol generating device 100 to reach an effective temperature more quickly.

The projections 140 on the inner surface of the side wall 126 extend towards the substrate holder 114 and, moreover, come into contact with it when it is introduced into the heating chamber 108 (see, for example, FIG. 6). This results in heating of the aerosol-forming substrate 128, also by conduction through the outer layer 132 of the substrate holder 114.

It will be appreciated that in order to conduct heat into the aerosol-forming substrate 128, the surface 145 of the protrusion 140 must be in mutual engagement with the outer layer 132 of the substrate holder 114. However, manufacturing tolerances may result in slight variations in the diameter of the substrate holder 114. In addition, due to the relatively soft and compressible properties of the outer layer 132 of the substrate holder 114 and the aerosol-forming substrate 128 held therein, any damage or mishandling of the substrate holder 114 may result in a reduction in diameter or a change in cross-sectional shape to an oval or elliptical shape. region where the outer layer 132 is expected to engage mutually with the surfaces 145 of the projections 140. Accordingly, any change in the diameter of the substrate holder 114 may result in reduced thermal contact between the outer layer 132 of the substrate holder 114 and the surface 145 of the projection 140, which negatively affects to conduct heat from the surface 145 of the protrusion 140 through the outer layer 132 of the substrate holder 114 into the aerosol-forming substrate 128. To mitigate the effect of any change in the diameter of the substrate holder 114 caused by manufacturing tolerances or damage, the protrusions 140 are preferably sized to extend into the heating chamber 108 a distance sufficient to cause compression of the substrate holder 114 and thus provide a secure fit. tension between the surfaces 145 of the projections 140 and the outer layer 132 of the substrate holder 114. This compression of the outer layer 132 of the substrate holder 114 may also cause a longitudinal mark to form on the outer layer 132 of the substrate holder 114 and provide a visible indication that the substrate holder 114 has been used.

In fig. 6(a) is an enlarged view of the heating chamber 108 and substrate holder 114. As can be seen, arrow B represents the air flow paths that provide the convective heating described above. As noted above, the heating chamber 108 may be in the form of a sleeve having a sealed, airtight base 112, which means that since air flow through the sealed, airtight base 112 is not possible, it will not be possible to enter the first end 134 by holding

- 7 043642 substrate body, air is forced to flow along the side of the substrate holder 114. As noted above, the projections 140 extend into the heating chamber 108 a distance at least sufficient to contact the outer surface of the substrate holder 114 and typically to cause compression of the substrate holder to at least some extent. Therefore, since the sectional view of FIG. 6(a) passes through the projections 140 on the left and right of the figure, there is no air gap all the way along the heating chamber 108 in the plane of the figure. Instead, the air flow paths (arrows B) are shown as dashed lines in the region of the projections 140, indicating that the air flow path is located in front of and behind the projections 140. In fact, comparison with Fig. 2(a) shows that the air flow paths occupy four evenly spaced gap regions between the four projections 140. Of course, in some situations there may be more or less than four projections 140, in which case it remains a true general feature that the flow paths air exists in the gaps between the protrusions.

Also in FIG. 6(a) highlights the deformation in the outer surface of the substrate holder 114 caused by its indentation by the projections 140 as the substrate holder 114 is inserted into the heating chamber 108. As noted above, the distance that the projections 140 extend into the heating chamber may advantageously be selected as follows: so that it is sufficient to cause compression of any substrate holder 114. This (sometimes permanent) deformation during heating may contribute to the stability of the substrate holder 114 in that the deformation of the outer layer 132 of the substrate holder 114 creates a denser region of the aerosol-forming substrate 128 near the first end 134 of the substrate holder 114. In addition, the resulting outer surface of the resulting shaped substrate holder 114 provides the effect of retaining at the edges of a denser region of the aerosol-forming substrate 128 near the first end 134 of the substrate holder 114. Overall, this reduces the likelihood of any loose substrate falling out of the first end 134 of the substrate holder 114, which could cause contamination of the heating chamber 108. This effect is beneficial because, as described above, heating the aerosol-forming substrate 128 may cause it to become dirty. shrinkage, which increases the likelihood of the loose aerosol-forming substrate 128 falling out of the first end 134 of the substrate holder 114. Due to the described deformation effect, this undesirable effect is weakened.

To ensure that the projections 140 engage in contact with the substrate holder 114 (the contact necessary to cause conductive heating, compression and deformation of the substrate forming an aerosol), the manufacturing tolerances of each of the projections 140 are taken into account; heating chamber 108; and a substrate holder 114.

For example, the inner diameter of the heating chamber 108 may be 7.6 ± 0.1 mm, the substrate holder 114 may have an outer diameter of 7.0 ± 0.1 mm, and the projections 140 may have a manufacturing tolerance of ±0.1 mm. In this example, assuming that the substrate holder 114 is mounted centrally in the heating chamber 108 (i.e., there is a uniform gap around the outside of the substrate holder 114), then the gap that each protrusion 140 must span in order to contact the substrate holder 114 , is in the range from 0.2 to 0.4 mm. In other words, since each projection 140 spans a certain radial distance, the smallest possible value for this example is half the difference between the smallest possible diameter of the heating chamber 108 and the largest possible diameter of the substrate holder 114 or [(7.6-0.1)-(7. 0+0.1)]/2=0.2 mm. The upper range limit for this example is (for similar reasons) half the difference between the largest possible diameter of the heating chamber 108 and the smallest possible diameter of the substrate holder 114 or [(7.6+0.1)-(7.0-0.1)] /2=0.4 mm. To ensure precise contact of the projections 140 with the substrate holder, it is clear that in this example each of them must extend at least 0.4 mm into the heating chamber. However, this does not take into account the manufacturing tolerance of the projections 140. If a projection of 0.4 mm is required, the actual manufacturing range is 0.4 ± 0.1 mm, or it varies from 0.3 to 0.5 mm. Some will not cover the maximum possible gap between the heating chamber 108 and the substrate holder 114. Therefore, the projections 140 in this example should be manufactured with a nominal projection distance of 0.5 mm, resulting in a range of values from 0.4 to 0.6 mm. This is sufficient to ensure that the projections 140 are always in contact with the substrate holder.

In general, if we write the inner diameter of the heating chamber 108 as D±δ _D , the outer diameter of the substrate holder 114 as d±5 _d , and the distance that the projections 140 extend into the heating chamber 108 as L±δ _L , then the distance which projections 140 are expected to extend into the heating chamber should be selected as:

where |6 _D | refers to the absolute value of the processing tolerance of the inner diameter of the heating chamber 108, |δd| refers to the absolute value of the processing tolerance of the outer diameter of the cartridge holder 114, and |δ _L | refers to the absolute value of the technological tolerance

- 8 043642 the distance to which the projections 140 extend into the heating chamber 108. To avoid any ambiguity, if the internal diameter of the heating chamber 108 is D±δ _D =7.6±0.1 mm, then |δ _D |=0.1 mm.

In addition, manufacturing tolerances may result in minor variations in the density of the aerosol-forming substrate 128 in the substrate holder 114 . These variations in the density of the aerosol-forming substrate 128 may exist in both axial and radial directions within a single substrate holder 114 or between different substrate holders 114 manufactured in the same batch. Accordingly, it will also be apparent that in order to ensure relatively uniform conduction of heat in the aerosol-forming substrate 128 in a particular substrate holder 114, it is important that the density of the aerosol-forming substrate 128 is also relatively uniform. To mitigate the effect of any discontinuities in the density of the aerosol-forming substrate 128, the projections 140 may be sized to extend into the heating chamber 108 a distance sufficient to cause compression of the aerosol-forming substrate 128 in the substrate holder 114, which may increase heat conduction through a substrate 128 that forms an aerosol by eliminating air gaps. In the illustrated embodiment, projections 140 extend into heating chamber 108 by approximately 0.4 mm are suitable. In other examples, the distance that the projections 140 extend into the heating chamber 108 can be defined as a percentage of the distance across the heating chamber 108. For example, the projections 140 may extend a distance of 3 to 7%, such as approximately 5% of the distance across the heating chamber 108 In another embodiment, the limited diameter defined by the projections 140 in the heating chamber 108 is from 6.0 to 6.8, more preferably from 6.2 to 6.5 mm and, in particular, 6.2 (±0.5 mm). Each of the plurality of projections 140 spans a radial distance of 0.2 to 0.8 mm, and most preferably 0.2 to 0.4 mm.

As for the projections/recesses 140, their width corresponds to the distance around the perimeter of the side wall 126. Likewise, the direction of their length extends transversely thereto, extending broadly from the base 112 to the open end of the heating chamber 108 or to the flange 138, and their height corresponds to the distance the extent that the projections extend from the side wall 126. It should be noted that the space between the adjacent projections 140, the side wall 126, and the outer layer 132 of the substrate holder 114 defines the area available for air flow. The result of this is that the smaller the distance between adjacent protrusions 140 and/or the height of the protrusions 140 (i.e., the distance that the protrusions 140 extend into the heating chamber 108), the more the user must suck the air in order to draw it in through the aerosol generating device 100 (this is known as increased draw resistance). It will be apparent that (assuming that the projections 140 are in contact with the outer layer 132 of the substrate holder 114) it is the width of the projections 140 that determines the reduction of the air flow path between the side wall 126 and the substrate holder 114. Conversely (also assuming that the projections 140 are in contact with the outer layer 132 of the substrate holder 114), increasing the height of the projections 140 results in greater compression of the aerosol substrate, which eliminates air gaps in the aerosol substrate 128 and also increases draw resistance. There are two parameters that can be adjusted to obtain a satisfactory tightening resistance that is neither too low nor too high. Heating chamber 108 can also be made larger to increase the air flow path between side wall 126 and substrate holder 114, but there is a practical limit to this before heater 124 begins to become ineffective when the gap becomes too large. Typically, a gap around the outer surface of the substrate holder 114 of 0.2 to 0.4 or 0.2 to 0.3 mm is a satisfactory compromise to allow the tightening resistance to be finely adjusted within tolerances by varying the size of the projections 140. The air gap around the outside of the substrate holder 114 can also be changed by changing the number of projections 140. Any number of projections 140 (one or more) provides at least some of the benefits set forth in the present invention (increasing heating area, providing compression, providing conductive heating aerosol-forming substrate 128, air gap adjustment, etc.). Four is the smallest number that will keep the substrate holder 114 securely in central (i.e., coaxial) alignment with the heating chamber 108. Another possible design has only three projections that are spaced 120 degrees apart. Designs containing fewer than four projections 140 tend to allow the substrate holder 114 to be pressed against a portion of the side wall 126 between two of the projections 140. It is clear that, given limited space, providing very large numbers of projections (e.g., thirty or more) has tending to a situation in which there is little or no gap between them, which may completely block the air flow path between the outer surface of the substrate holder 114 and the inner surface of the side wall 126, which significantly reduces the ability of the aerosol generating device to provide convective heating. However, such designs can still be used in combination with

- 9 043642 the ability to provide an opening in the center of the base 112 to form a channel for air flow. Typically, the projections 140 are evenly distributed around the perimeter of the side wall 126, which can help ensure uniform compression and heating, although some options may have an asymmetrical placement depending on the exact result desired.

It will be appreciated that the size and number of projections 140 also provide the ability to adjust the balance between conductive and convective heating. By increasing the width of the protrusion 140 (the distance that the protrusion 140 extends around the perimeter of the side wall 126) in contact with the substrate holder 114, the available perimeter of the side wall 126 acting as a channel for air flow is reduced (arrows B in FIG. 6). and 6(a)), thereby reducing the convective heating provided by the aerosol generating device 100. However, as the wider protrusion 140 engages the substrate holder 114 over a larger portion of the perimeter, the conductive heating provided by the aerosol generating device 100 increases. As more protrusions 140 are added, a similar effect can be observed in that the convective perimeter of the side wall 126 decreases as the conductive channel increases by increasing the total contact surface area between the protrusion 140 and the substrate holder 114. It should be noted that the length of the projection 140 also reduces the volume of air in heating chamber 108 that is heated by the heater 124 and reduces convective heating, while increasing the contact surface area between the projection 140 and the substrate holder and increasing conductive heating. Increasing the distance that each projection 140 extends into the heating chamber 108 may improve conductive heating without significantly reducing convective heating. Therefore, the aerosol generating device 100 can be configured to balance conductive and convective heating by varying the number and size of projections 140 as described above. The heat confinement effect due to the relatively thin side wall 126 and the use of a material with relatively low thermal conductivity (eg, stainless steel) provides that conduction heating is a suitable means of transferring heat to the substrate holder 114 and, by extension, to the aerosol-forming substrate 128, since the heated portions of the sidewall 126 may broadly correspond to the locations of the projections 140, meaning that the generated heat is conducted toward the substrate holder 114 by the projections 140 and is not conducted away from it. At locations that are heated but do not correspond to the projections 140, heating of the side wall 126 results in the convective heating described above.

As shown in FIG. 1-6, the projections 140 are elongated, that is, their length is greater than their width. In some cases, the projections 140 may be five, ten, or even twenty-five times their width in length. For example, as noted above, in one example, the projections 140 may extend 0.4 mm into the heating chamber 108 and may also be 0.5 mm wide and 12 mm long. These dimensions are suitable for heating chamber 108 with a length of 30 to 40 mm. In this example, the projections 140 do not extend the full length of the heating chamber 108 because in the illustrated example they are shorter than the heating chamber 108. Therefore, each projection 140 has a top edge 142a and a bottom edge 142b. The top edge 142a is the portion of the projection 140 closest to the open end 110 of the heating chamber 108 and also closest to the flange 138. The bottom edge 142b is the end of the projection 140 closest to the base 112. It can be seen that above the top edge 142a (closer to the open end than the top edge 142a) and below the bottom edge 142b (closer to the base 112 than the bottom edge 142b), the side wall 126 does not have projections 140, that is, in these parts, the side wall 126 is not deformed or dented. In some examples, the projections 140 are longer and extend the entire length to the top and/or bottom of the side wall 126 such that one or both of the following is true: the top edge 142a is aligned with the open end 110 of the heating chamber 108 (or flange 138); and the bottom edge 142b is aligned with the base 112. Moreover, in these cases there may not even be a top edge 142a and/or a bottom edge 142b.

It may be advantageous that the projections 140 do not extend the entire length of the heating chamber 108 (eg, from the base 112 to the flange 138). At the upper end, as will be described below, the upper edge 142a of the protrusion 140 can be used as an indicator for the user to ensure that he does not insert the substrate holder 114 an excessive distance into the aerosol generating device 100. However, it may be useful to heat not only the areas of the substrate holder 114 containing the aerosol-forming substrate 128, but also other areas. The reason for this is that once the aerosol is generated, it is useful to keep it at a high temperature (above room temperature, but not so hot that it burns the user) to prevent re-condensation, which in turn degrades the user's experience. Therefore, the effective heating region of heating chamber 108 extends beyond the expected location of aerosol-forming substrate 128 (ie, above heating chamber 108, toward the open end). This means that the heating chamber 108 extends above the top edge 142a of the projection 140 or, equivalently, that the projection 140 does not extend the entire length to the open end of the heating chamber 108. Likewise

- 10 043642 compression of the aerosol-forming substrate 128 at the end 134 of the substrate holder 114 inserted into the heating chamber 108 may cause some of the aerosol-forming substrate 128 to fall out of the substrate holder 114 and contaminate the heating chamber 108. Therefore, it may be advantageous to the lower edge 142b of the projections 140 is further from the base 112 than the expected position of the end 134 of the substrate holder 114.

In some embodiments, the projections 140 are not elongated and have a width approximately equal to their length. For example, they may have a width equal to their height (eg, have a square or round profile when viewed in the radial direction), or they may be two to five times as long as they are wide. It should be noted that the centering effect provided by the projections 140 can be achieved even when the projections 140 are not elongated. In some examples, these may be a plurality of sets of projections 140, such as a top set proximal to the open end of heating chamber 108 and a bottom set spaced from the top set and proximate the base 112. This may help ensure that the substrate holder 114 is held in coaxial alignment while simultaneously by reducing the tightening resistance introduced by a single set of protrusions 140 at equal distances. The two sets of projections 140 may be substantially the same, or they may vary in length or width or in the number or placement of projections 140 located around the circumference of the side wall 126.

In a side view, the projections 140 are shown as having a trapezoidal profile. By this it is meant that the profile along the length of each protrusion 140, such as the average longitudinal cross section of the protrusion 140, is approximately trapezoidal. That is, the top edge 142a is broadly flat and tapers to meet the side wall 126 near the open end 110 of the heating chamber 108. In other words, the top edge 142a has a beveled profile shape. Likewise, the protrusion 140 has a bottom portion 142b that is broadly flat and tapered to meet the side wall 126 near the base 112 of the heating chamber 108. That is, the bottom edge 142b has a beveled profile shape. In other embodiments, the top and/or bottom edges 142a, 142b do not taper toward the side wall 126, but instead extend from the side wall 126 at an angle of approximately 90 degrees. In other embodiments, the top and/or bottom edges 142a, 142b have a curved or rounded shape. The junction of the top and/or bottom edges 142a, 142b is, broadly speaking, a flat area that engages and/or compresses the substrate holder 114. The flat contact portion can help ensure uniform compression and conductive heating. In other examples, the flat portion may instead be a curved portion that is curved outward to contact the substrate holder 128, such as having a polygonal or curved profile (eg, a circular segment).

In cases where the projections 140 have a top edge 142a, the projections 140 also act to prevent over-insertion of the substrate holder 114. As most clearly shown in FIG. 4 and 6, the substrate holder 114 has a lower portion containing the aerosol-forming substrate 128 that terminates some distance along the substrate holder 114 at the boundary of the aerosol-forming substrate 128. The aerosol-forming substrate 128 is typically more compressible than other areas 130 of the substrate holder 114 . Therefore, the user inserting the substrate holder 114 feels an increase in resistance when the top edge 142a of the protrusions 140 aligns with the boundary of the aerosol-forming substrate 128 due to the reduced compressibility of other areas 130 of the substrate holder 114. To achieve this result, the portion(s) of the base 112 in contact with which the substrate holder 114 is located must be positioned relative to the top edge 142a of the projection 140 at a distance equal to the length of the substrate holder 114 occupied by the substrate 128. forming an aerosol. In some examples, the aerosol-forming substrate 128 occupies approximately 20 mm of the substrate holder 114, so the distance between the top edge 142a of the projection 140 and the portions of the base that the substrate holder 114 contacts when inserted into the heating chamber 108 is also approximately 20 mm.

As shown, the base 112 also includes a platform 148. The platform 148 is formed in a single step in which the base 112 is forced from below (for example, by hydraulic molding or mechanical pressing as part of the formation of the heating chamber 108) so as to leave a depression on the outer surface (bottom surface) of the base 112 and a platform 148 on the inner surface (the top surface inside the heating chamber 108) of the base 112. If the platform 148 is formed in this manner, for example with a corresponding depression, these terms are used interchangeably. In other cases, platform 148 may be formed from a separate piece that is attached to base 112 separately, or by cutting away portions of base 112 so that platform 148 remains; in each of these two cases the corresponding depression is not necessary. The latter cases may allow greater variety of shapes for the platform 148 to be achieved since they do not rely on deformation of the base 112, which (while a convenient method) limits the complexity with which the shape can be selected. Although the shape shown is broadly circular, there is, of course, a wide variety of shapes that will achieve the desired results, detailed in

- 11 043642 of the present invention, including but not limited to: polygonal shapes, curved shapes, including many shapes of one or more of these types. Moreover, although the platform 148 is shown as being centrally located, in some cases there may be one or more platform elements located off-center, such as at the edges of the heating chamber 108. Typically, the platform 148 is broadly flat the upper part, however, hemispherical platforms or platforms in the shape of a dome, rounded at the upper part, are also provided.

As noted above, the distance between the top edge 142a of the protrusion 140 and the portions of the base 112 that the substrate holder 114 contacts can be carefully selected to match the length of the aerosol-forming substrate 128 to provide an indication to the user that he has inserted the substrate holder 114 into the aerosol generating device 100 to the required distance. In cases where there is no platform 148 on the base 112, this simply means that the distance from the base 112 to the top edge 142a of the projection 140 must match the length of the aerosol-forming substrate 128. If a platform 148 is present, then the length of the aerosol-forming substrate 128 should correspond to the distance between the top edge 142a of the projection 140 and the uppermost portion of the platform 148 (i.e., in some examples, the portion closest to the open end 110 of the heating chamber 108). In another example, the distance between the top edge 142a of the projection 140 and the uppermost portion of the platform 148 is slightly less than the length of the aerosol-forming substrate 128. This means that the tip 134 of the substrate holder 114 must extend slightly beyond the uppermost portion of the platform 148, thereby causing the aerosol-forming substrate 128 to compress at the end 134 of the substrate holder 114. Moreover, this compression effect can occur even in examples where the projections 140 on the inner surface of the side wall 126 are absent. This compression may help prevent the aerosol-forming substrate 128 at the end 134 of the substrate holder 114 from falling out into the heating chamber 108, thereby reducing the need for cleaning the heating chamber 108, which can be a complex and difficult task. In addition, compression promotes compression of the end 134 of the substrate holder 114, which thus reduces the above-described effect when compression of this area using the projections 140 extending from the side wall 126 is inappropriate for the reason that they tend to increase the likelihood of the substrate 128 forming falling out. aerosol, from substrate holder 114.

The platform 148 also provides an area in which any aerosol-forming substrate 128 dropped from the substrate holder 114 can be collected without blocking the air flow path to the tip 134 of the substrate holder 114 . For example, the platform 148 divides the lower end of the heating chamber 108 (i.e., the portions closest to the base 112) into raised portions forming the platform 148 and lower portions forming the remainder of the base 112. The lower portions may receive loose particles of the substrate 128 forming aerosol falling out of the substrate holder 114, while air may still flow over these loose particles of aerosol-forming substrate 128 to the end of the substrate holder 114. To achieve this result, the platform 148 may be positioned approximately 1 mm higher than the rest of the base 112. The platform 148 may have a diameter smaller than the diameter of the substrate holder 114 so that it does not impede the flow of air through the aerosol-forming substrate 128. Preferably, platform 148 has a diameter of 0.5 mm to 0.2 mm, most preferably 0.45 mm to 0.35 mm, such as 0.4 mm (±0.3 mm).

The aerosol generating device 100 has a user operated button 116. In the first embodiment, the user-operable button 116 is located on the side wall 118 of the shell 102. The user-actuable button 116 is positioned such that when the user-actuable button 116 is activated, for example, by pressing the button 116 When activated by the user, the aerosol generating device 100 is activated to heat the aerosol generating substrate 128 to generate an inhalable aerosol. In some embodiments, the user-actuated button 116 is also configured to allow the user to activate other functions of the aerosol generating device 100 and/or provide a light signal to indicate the status of the aerosol generating device 100. In other examples, a separate indicator light or indicator lights (eg, one or more LEDs or other suitable light sources) may be provided to indicate the status of the aerosol generating device 100. In the context of the present invention, status may mean one or more of the following: battery power remaining, heater status (eg, on, off, error, etc.), device status (eg, ready to tighten or not ready), or other indication of status , for example, error modes, indications of the number of puffs or the number of full substrate holders 114 consumed or remaining until the power source is completely discharged, etc.

In the first embodiment, the aerosol generating device 100 is electrically powered. That is, it is configured to heat the aerosol-forming substrate 128 using electrical power. For this purpose, the aerosol generating device 100 has a power source 120, such as a battery. Power supply 120 is connected to control circuit 122

- 12 043642 nia. The control circuit 122, in turn, is connected to the heater 124. The button 116, actuated by the user, is configured to connect and disconnect the power source 120 from the heater 124 through the control circuit 122. In this embodiment, the power supply 120 is located towards the first end 104 of the aerosol generating device 100. This allows the power source 120 to be located at a distance from the heater 124 located towards the second end 106 of the aerosol generating device 100. In other embodiments, heating chamber 108 is heated by other means, such as by burning a combustible gas.

The heater 124 is attached to the outer surface of the heating chamber 108. The heater 124 is provided on a metal layer 144, which itself is provided in contact with the outer surface of the side wall 126. The metal layer 144 defines a strip around the heating chamber 108 corresponding to the shape of the outer surface of the side wall 126. Heater 124 is shown to be centrally mounted on the metal layer 144, with the metal layer 144 extending equal distances up and down behind the heater 124. As shown, the heater 124 is located entirely on the metal layer 144 such that the metal layer 144 covers an area larger than the area occupied by the heater 124. Heater 124, as shown in FIG. 1-6 is attached to the middle portion of the heating chamber 108 between the base 112 and the open end 110 and is attached to the outer surface area coated with the metal layer 114. It should be noted that in other embodiments, the heater 124 may be coupled to other portions of the heating chamber 108 or may be contained in the side wall 126 of the heating chamber 108, and it is not significant that the outer portion of the heating chamber 108 contains a metal layer 144.

As shown in FIG. 7, heater 124 includes a heating element 164, electrical connection paths 150, and a protective film 166. The heating element 164 is configured such that when current passes through the heating element 164, the heating element 164 heats up and its temperature increases. The heating element 164 is shaped such that it does not contain any sharp corners. Sharp corners may contain hot spots in heater 124 or form melting points. The heating element 164 also has a uniform width, and portions of the element 164 that extend close to each other are kept at approximately equal distances. In the heating element 164 of FIG. 7 shows two resistive paths 164a, 164b, each of which follows a serpentine path across an area of the heater 124 that covers as much area as possible while still satisfying the criteria described above. These paths 164a, 164b in FIG. 7 are electrically parallel to each other. It should be noted that other numbers of paths may be used, such as three paths, one path, or multiple paths. Paths 164a, 164b do not intersect, as this would create a short circuit. Heating element 164 is configured as resistive to produce the correct energy density for the desired level of heating. In some examples, heating element 164 has a resistance of 0.4 to 2.0, particularly preferably 0.5 to 1.5, and more particularly 0.6 to 0.7 ohms.

Electrical connection tracks 150 are shown as part of heater 124, but in some embodiments they may be replaced by wires or other connecting elements. Electrical connections 150 are used to supply power to heating element 164 and form a circuit with power supply 120 . Electrical connection paths 150 are shown extending vertically downward from heating element 164. When heater 124 is in place, electrical connections 150 extend beyond base 112 of heating chamber 108 and through base 156 of insulating element 152 to connect to control circuitry 122.

The protective film 166 can either be a single sheet with a heating element 164 attached, or it can form a wrap in which the heating element is located between two sheets 166a, 166b. In some embodiments, the protective film 166 is formed from polyimide. In some embodiments, the thickness of the protective film 166 is minimized to reduce the thermal capacity of the heater 124. For example, the thickness of the protective film 166 may be 50, or 40, or 25 microns.

Heating element 164 is attached to side wall 108. In FIG. 7, heating element 164, through careful selection of the size of heater 124, is designed to wrap once around heating chamber 108. This provides approximately uniform distribution of the heat generated by heater 124 near the surface covered by heater 124. It should be noted that in some examples, instead of one complete rotation, heater 124 can be wrapped around heating chamber 108 an integer number of times.

It should also be noted that the height of the heater 124 is approximately 14 to 15 mm. The circumference of the heater 124 (or its length before use in the heating chamber 108) is from approximately 24 to 25 mm. The height of the heating element 164 may be less than 14 mm. This allows the heating element 164 to be located entirely within the protective film 166 of the heater 124 with a border around the heating element 164. Therefore, the area covered by the heater 124 may, in some embodiments, be approximately 3.75 cm ² .

- 13 043642

The power used by the heater 124 is supplied by a power source 120, which in this embodiment is in the form of a power cell (or battery). The voltage provided by power supply 120 is a regulated voltage or boost voltage. For example, power supply 120 may be configured to generate a voltage in the range of 2.8 to 4.2 V. In one example, power supply 120 is configured to generate a voltage of 3.7 V. Assuming the approximate resistance of heating element 164 in one embodiment implementation equal to 0.6 ohms and an approximate voltage of 3.7 V, this will provide a power output to the heating element 164 of approximately 30 W. It should be noted that based on approximate resistances and voltages, the output power can range from 15 to 50 W. The battery forming the power source 120 may be a rechargeable battery or, alternatively, may be a disposable power cell 120. The power supply is typically designed so that it can supply power for 20 or more heating cycles. This allows the user to use a full stack of 20 substrate holders 114 per charge of aerosol generating device 100. The battery may be a lithium-ion battery or any other type of commercially available battery. It may be, for example, an 18650 battery or an 18350 battery. If the battery is an 18350 battery, the aerosol generating device 100 may be configured to store a charge sufficient for 12 heating cycles or even 20 heating cycles. heating, which allows the user to consume 12 or even 20 substrate holders 114.

One important quantity for heater 124 is the power it produces per unit area. It is a measure of how much heat can be provided by heater 124 to its contact area (in this case, heating chamber 108). For the examples described, it is in the range from 4 to 13.5 W/ ^cm2 . Depending on the design, heaters are typically rated for maximum power densities of 2 to 10 W/ ^cm2 . Therefore, in some of these embodiments, a layer 144 of copper or other conductive metal may be provided on the heating chamber 108 to efficiently conduct heat from the heater 124 and reduce the likelihood of damage to the heater 124.

The power delivered by heater 124 may be constant in some embodiments and may not be constant in other embodiments. For example, heater 124 may provide variable power over an operating cycle, or more specifically, a pulse width modulation cycle. This allows power to be delivered in pulses and the time-averaged power output of heater 124 to be easily controlled by simply selecting the timing of the on and off states. The power output of heater 124 can also be controlled using additional controls such as current or voltage control.

As shown in FIG. 7, the aerosol generating device 100 has a temperature sensor 170 for detecting the temperature of the heater 124 or the environment surrounding the heater 124. The temperature sensor 170 may be, for example, a thermistor, a thermocouple, or any other thermometer. For example, a thermistor may be formed from a glass bead containing resistive material connected to a voltmeter and having a known current flow through it. Thus, as the temperature of the glass changes, the resistance of the resistive material changes in a predictable manner, and therefore the temperature can be determined from the voltage drop across it at constant current (constant voltage modes are also possible). In some embodiments, the temperature sensor 170 is located on the surface of the heating chamber 108, such as in a dimple formed in the outer surface of the heating chamber 108. The dimple may be one of the dimples described elsewhere in the present invention, for example, as part of the projections 140, or may be a recess specifically provided to hold the temperature sensor 170 . In the illustrated embodiment, a temperature sensor 170 is provided on the protective layer 166 of the heater 124. In other embodiments, the temperature sensor 170 is integral with the heating element 164 of the heater 124 in that the temperature is determined by monitoring changes in the resistance of the heating element 164.

In the aerosol generating device 100 according to the first embodiment, an important parameter is the time until the first puff after the aerosol generating device 100 is started. The user of the aerosol generating device 100 will find it preferable to begin inhaling the aerosol from the substrate holder 128 as soon as possible, with minimal delay time between starting the aerosol generating device 100 and inhaling the aerosol from the substrate holder 128. Therefore, during the first heating stage, power supply 120 supplies 100% of available power to heater 124, for example by setting the operating cycle to always on or by controlling the product of voltage and current until it reaches its maximum possible value. This may take a period of 30 seconds, or more preferably a period of 20 seconds, or any period until the temperature sensor 170 gives a reading corresponding to 240°C. Typically the substrate holder 114 can be

- 14 043642 can operate optimally at 180 °C, however, it may still be advantageous to heat the temperature sensor 170 above this temperature so that the user can remove the aerosol from the substrate holder 114 as quickly as possible. The reason for this is that the temperature of the aerosol-forming substrate 128 typically lags behind (i.e., is lower than) the temperature detected by the temperature sensor 170 because the aerosol-forming substrate 128 is heated by convection of heated air through the aerosol-forming substrate 128. aerosol, and as heat is conducted between the projections 140 and the outer surface of the substrate holder 114. In comparison, temperature sensor 170 is held in satisfactory thermal contact with heater 124 and therefore measures a temperature near the temperature of heater 124 rather than the temperature of the aerosol-forming substrate 128. In fact, accurately measuring the temperature of the aerosol-forming substrate 128 can be difficult, so the heating cycle is often determined empirically by testing different heating profiles and heater temperatures and monitoring the aerosol generated by the aerosol-forming substrate 128 against the various aerosol components generated at a given temperature. Optimal cycles deliver aerosols as quickly as possible while eliminating the generation of combustion products due to overheating of the aerosol-forming substrate 128.

The temperature sensed by temperature sensor 170 can be used to set the level of power delivered by power element 120, for example by forming a feedback loop in which the temperature sensed by temperature sensor 170 is used to control the power cycle of the heater. The heating cycle described below may take place for a case in which the user wishes to consume one substrate holder 114.

In the first embodiment, the heater 124 extends around the heating chamber 108. That is, the heater 124 surrounds the heating chamber 108. In more detail, the heater 124 extends around the side wall 126 of the heating chamber 108, but not around the base 112 of the heating chamber 108. The heater 124 does not extend throughout side wall 126 of the heating chamber 108. Instead, it extends completely around the side wall 126, but only partially along the length of the side wall 126, where the length in the context of the present invention is the distance from the base 112 to the open end 110 of the heating chamber 108. In other embodiments implementation, heater 124 extends the entire length of side wall 126. In other embodiments, heater 124 includes two heating portions separated by a gap leaving a central portion of heating chamber 108 open, such as a portion of side wall 126 midway between base 112 and open end 110 of heating chamber 108. In other embodiments, because the heating chamber 108 is sleeve-shaped, the heater 110 is similarly sleeve-shaped, such that it extends completely around the base 112 of the heating chamber 108. In other embodiments, the heater 124 includes a plurality of heating elements 164 distributed proximate the heating chamber 108. in some embodiments, there are gaps between the heating elements 164; in other embodiments, they overlap with each other. In some embodiments, heating elements 164 may be spaced around the circumference of heating chamber 108 or side wall 126, such as laterally; in other embodiments, heating elements 164 may be spaced along the length of heating chamber 108 or side wall 126, such as longitudinally. It should be understood that the heater 124 according to the first embodiment is provided on an outer surface of the heating chamber 108 outside the heating chamber 108. To enable satisfactory heat transfer between the heater 124 and the heating chamber 108, the heater 124 is provided in satisfactory thermal contact with the heating chamber 108.

The metal layer 144 may be formed from copper or any other material (eg, metal or alloy) with high thermal conductivity, such as gold or silver. In the context of the present invention, the term high thermal conductivity may refer to a metal or alloy having a thermal conductivity of 150 W/m-K or more. The metal layer 144 may be deposited by any suitable method, such as electrodeposition. Other methods for applying layer 144 include bonding metal tape to heating chamber 108, chemical vapor deposition, physical vapor deposition, etc. Although electrodeposition is a convenient method for depositing layer 144, it requires that the portion on which layer 144 is coated be electrically conductive. This is not required in other deposition methods, and these other methods open up the possibility of forming the heating chamber 108 from non-conductive materials, such as ceramics, which may have beneficial thermal properties. Also, if a layer is described as metallic, although this would normally be understood to mean formed from a metal or alloy, in this context it refers to a material with a relatively high thermal conductivity (>150 W/m-K). If the metal layer 144 is electrodeposited onto the side wall 126, it may be necessary to first form a tie layer to ensure adhesion of the electrodeposited layer to the outer surface. For example, if the metal layer 144 is copper and the side wall 126 is stainless steel, to provide

- 15 043642 To ensure satisfactory adhesion, a nickel layer of tightening is often used. Electrodeposited layers and deposited layers have the advantage of direct contact between the metal layer 144 and the side wall material 126, thereby increasing the thermal conductivity between the two elements.

Whatever method is used to form the metal layer 144, the thickness of the layer 144 is typically somewhat less than the thickness of the side wall 126. For example, the range of metal layer thicknesses can be from 10 to 50 or from 10 to 30, such as approximately 20 microns. When a tie layer is used, it is even thinner than the metal layer 144, for example 10 or even 5 µm thick. As described in more detail below, the purpose of the metal layer 144 is to distribute the heat generated by the heater 124 over an area larger than the area occupied by the heater 124. Once this effect is successfully achieved, the benefit of further increasing the thickness of the metal layer 144 becomes small, since it only increases the heat capacity and reduces the efficiency of the aerosol generating device 100.

From fig. 1-6, it will be apparent that the metal layer 144 extends only over a portion of the outer surface of the side wall 126. This not only reduces the heat capacity of the heating chamber 108, but also allows the heating region to be defined. In a broad sense, the metal layer 144 has a greater thermal conductivity than the side wall 126, so the heat generated by the heater 124 quickly spreads over the area covered by the metal layer 144, however, because the side wall 126 is not only thin, but also With a relatively lower thermal conductivity than the metal layer 144, the heat remains relatively localized in the areas of the side wall 126 covered by the metal layer 144. Selective electrodeposition is achieved by masking portions of the heating chamber 108 with a suitable tape (eg, polyester or polyimide) or silicone rubber casting. Other deposition methods may use other tapes and masking methods as needed.

As shown in FIG. 1-6, the entire length of the metal layer 144 overlaps with the heating chamber 108, along which the projections/recesses 140 extend. This means that the projections 140 are heated by the thermal conductivity of the metal layer 144, which in turn allows the projections 140 to provide the above-described conductive heat. The extent of the metal layer 144 broadly corresponds to the extent of the heating region, that is, it is often not necessary to extend the metal layer to the top and bottom portions of the heating chamber 108 (ie, the portions proximal to the open end and base 112). As noted above, the region of the substrate holder 114 to be heated begins a short distance above the boundary of the aerosol-forming substrate 128 and extends toward the end 134 of the substrate holder 114, but in many cases does not include the end 134 of the substrate holder 114. As noted above, the metal layer 144 acts such that the heat generated by the heater 124 is distributed over an area larger than the area occupied by the heater 124 itself. This means that more energy can be applied to the heater 124 than would be nominally the case based on its design value in W/cm and the surface area occupied by the heater 124, since the heat generated is distributed over a larger area, therefore the effective area of the heater 124 is greater than the surface area actually occupied by the heater 124.

Since the heating zone may be defined by portions of the side wall 126 that are coated with the metal layer 144, precise placement of the heater 124 on the outside of the heating chamber 108 is less critical. For example, rather than requiring heater 124 to be aligned at a specific distance from the top or bottom of side wall 126, metal layer 144 may instead be formed in a very specific area, and heater 124 placed on top of metal layer 144 distributes heat across the region of metal layer 144 , or heating zone as described above. The masking process is often easier to standardize for electrodeposition or deposition than to precisely align the heater 124.

Likewise, if there are projections 140 formed by pressing in the side wall 126, the recesses represent portions of the side wall 126 that will not be in contact with the heater 124 wrapped around the heating chamber 108; instead, heater 124 tends to bridge the cavity while maintaining a gap. The metal layer 144 may help reduce this effect due to the fact that, by conduction through the metal layer 144, heat is received from the heater 124 even by those portions of the side wall 126 that are not in direct contact with the heater 124. In some cases, the heating element 164 may be located with the ability to minimize the overlap between the heating element 164 and the recess on the outer surface of the side wall 126, for example, by positioning the heating element 164 so that it intersects the recess, but does not extend along the recess. In other cases, the heater 124 is located on the outer surface of the side wall 126 such that the portions of the heater 124 lying on top of the dimples are gaps between the heating elements 164. Whatever method is chosen to reduce the effect of the heater 124 lying on top of the dimple, the metal layer 144 weakens this effect by conducting heat into the cavity. In addition, the metal layer 144 provides

- 16 043642 provides additional thickness in the recessed areas of the side walls 126, thereby providing additional structural support to these areas. Moreover, the additional thickness provided by the metal layer 126 increases the strength of the thin side wall 126 in all portions covered by the metal layer 144.

The metal layer 144 may be formed before or after the step of dimpling the outer surface of the side wall 126 to provide projections 140 extending into the heating chamber 108. It is preferable to form the dimples before forming the metal layer because such processes occur after the metal layer 144 is formed. , such as annealing, may damage the metal layer 144, and stamping the side wall 126 to form the projections 140 becomes more difficult due to the increased thickness of the side wall 126 in combination with the metal layer 144. However, in the case where the depressions are formed before the formation of the metal layer 144 on side wall 126, it is much easier to form the metal layer 144 to extend beyond the recesses (ie, above and below) since masking the outer surface of the side wall 126 to extend into the recess is difficult. The presence of any gap between the mask and the side wall 126 may result in the deposition of a metal layer 144 under the mask.

A thermal insulating layer 146 is wrapped around the heater 124. This layer 146 is under tension, thereby providing a compressive force against the heater 124 that holds the heater 124 tightly against the outer surface of the side wall 126. Advantageously, this thermal insulating layer 146 is a heat shrink material. This allows the insulating layer 146 to be tightly wrapped around the heating chamber (over heater 124, metal layer 144, etc.) and then heated. When heated, the insulating layer 146 contracts and presses the heater 124 tightly against the outer surface of the side wall 126 of the heating chamber 108. This eliminates any air gaps between the heater 124 and the side wall 126, and keeps the heater 124 in satisfactory thermal contact with the side wall. This, in turn, provides high efficiency because the heat generated by the heater 124 heats the side wall (and then the aerosol-forming substrate 128) rather than being wasted in heating the air or lost in other ways.

In a preferred embodiment, a heat shrink material is used, such as treated polyimide tape, which shrinks in only one dimension. For example, in the example of a polyimide tape, the tape may be configured to shrink only in the length direction. This means that the tape can be wrapped around the heating chamber 108 and the heater 124 and that when heated, it will contract and press the heater 124 against the side wall 126. Because the insulating layer 146 shrinks in the length direction, the force thus generated is uniform and inward. Where the tape shrinks in the transverse direction (widthwise), it can cause the heater 124 or the tape itself to collapse. This, in turn, may cause gaps to form and reduce the efficiency of the aerosol generating device 100.

With reference to FIG. 3-6, the substrate holder 114 contains a prepackaged amount of aerosol-forming substrate 128 along with an aerosol collection area 130, which are wrapped in an outer layer 132. The aerosol-forming substrate 128 is disposed toward the first end 134 of the substrate holder 114. The aerosol-forming substrate 128 extends across the entire width of the substrate holder 114 within the outer layer 132. They also abut each other at some distance along the substrate holder 114, meeting at the boundary. In general, the substrate holder 114 is generally cylindrical. An aerosol generating device 100 is shown in FIG. 1 and 2 without substrate holder 114. In fig. 3 and 4, the substrate holder 114 is shown above the aerosol generating device 100, but is not loaded into the aerosol generating device 100. In fig. 5 and 6, substrate holder 114 is shown loaded into aerosol generating device 100.

When the user wants to use the aerosol generating device 100, the user first loads the substrate holder 114 into the aerosol generating device 100. This involves introducing the substrate holder 114 into the heating chamber 108.

The substrate holder 114 is inserted into the heating chamber 108 in such an orientation that the first end 134 of the substrate holder 114, towards which the aerosol-forming substrate 128 is located, enters the heating chamber 108. The substrate holder 114 is inserted into the heating chamber 108 until the first end 134 of the substrate holder 114 will rest against a platform 148 extending inwardly from the base 112 of the heating chamber 108, that is, until the substrate holder 114 cannot be inserted further into the heating chamber 108. In the illustrated embodiment, as described above, there is an additional interaction effect between the upper edge 142a of the projections 140 and the boundary of the aerosol generating substrate 128 with the less compressible adjacent region of the substrate holder 114, which alerts the user that the substrate holder 114 has been inserted into the aerosol generating device 100 a sufficient distance. As can be seen in FIG. 3 and 4, when the substrate holder 114 is inserted into the heating chamber 108 as far as possible, only a portion of the length of the substrate holder 114 is inside the heating chamber 108. The remainder of the length of the substrate holder 114 extends from the heating chamber 108. At least a portion

- 17 043642 the remaining length of the substrate holder 114 also protrudes from the second end 106 of the aerosol generating device 100. In the first embodiment, the entire remaining length of the substrate holder 114 protrudes from the second end 106 of the aerosol generating device 100. That is, the open end 110 of the heating chamber 108 coincides with the second end 106 of the aerosol generating device 100. In other embodiments, the aerosol generating device 100 may accommodate all or substantially all of the substrate holder 114 without the substrate holder 114 protruding or substantially protruding from the aerosol generating device 100.

When the substrate holder 114 is inserted into the heating chamber 108, the aerosol-forming substrate 128 in the substrate holder 114 is at least partially located in the heating chamber 108. In the first embodiment, the aerosol-forming substrate 128 is completely contained in the heating chamber 108. Moreover, the prepackaged amount of aerosol-forming substrate 128 in the substrate holder 114 is positioned to extend along the substrate holder 114 from the first end 134 of the substrate holder 114 to a distance that is approximately (or even exactly) equal to the internal height of the heating chamber 108 from the base 112 to the open end 110 of the heating chamber 108. This is substantially equal to the length of the side wall 126 of the heating chamber 108 within the heating chamber 108.

When the substrate holder 114 is loaded into the aerosol generating device 100, the user turns on the aerosol generating device 100 using the user-operated button 116. This causes power from power supply 120 to be supplied to heater 124 via (and under the control of) control circuit 122 . The heater 124 causes heat to be conducted through the projections 140 into the aerosol-forming substrate 128, heating the aerosol-forming substrate 128 to a temperature at which it can begin to release steam. Once heated to a temperature at which steam can begin to be released, the user can inhale the steam by sucking the steam through the second end 136 of the substrate holder 114. That is, steam is generated from the aerosol-forming substrate 128 located at the first end 134 of the substrate holder 114 in the heating chamber 108, and is drawn along the length of the substrate holder 114 through the steam collection area 130 in the substrate holder 114 into the second end 136 of the substrate holder through which it enters the user's mouth. This steam flow is shown in FIG. 6 arrow A.

It is understood that when the user sucks in steam in the direction of arrow A in FIG. 6, steam flows from a region near aerosol-forming substrate 128 into heating chamber 108. By this action, ambient air is drawn into heating chamber 108 (along the flow paths indicated in FIG. 6 by arrows B and shown in more detail in FIG. 6 (A)) from the environment surrounding the aerosol generating device 100. This ambient air is then heated by heater 124 and in turn heats aerosol-forming substrate 128, causing an aerosol to be generated. More specifically, in the first embodiment, air enters the heating chamber 108 through a gap provided between the side wall 126 of the heating chamber 108 and the outer layer 132 of the substrate holder 114. To this end, the outer diameter of the substrate holder 114 is smaller than the inner diameter of the heating chamber 108. More specifically, in the first embodiment, the heating chamber 108 has an inner diameter (where no projection is provided, such as where the projections 140 are missing, or between them) 10 or less, preferably 8 or less, and most preferably about 7.6 mm. This allows the substrate holder 114 to have a diameter of approximately 7.0 mm (±0.1 mm) (when not compressed by the projections 140). This corresponds to an outer circumference length of 21 to 22, or more preferably 21.75 mm. In other words, the distance between the substrate holder 114 and the side wall 126 of the heating chamber 108 is most preferably approximately 0.1 mm. In other embodiments, the gap is at least 0.2, and in some examples up to 0.3 mm. Arrows B in Fig. 6 shows the direction in which air is drawn into the heating chamber 108.

When a user activates the aerosol generating device 100 by operating a user-operated button 116, the aerosol generating device 100 heats the aerosol generating substrate 128 to a temperature sufficient to cause portions of the aerosol generating substrate 128 to evaporate. . In more detail, the control circuit 122 supplies power from the power supply 120 to the heater 124 to heat the aerosol-forming substrate 128 to a first temperature. When the aerosol generating substrate 128 reaches the first temperature, the components of the aerosol generating substrate 128 begin to evaporate, that is, the aerosol generating substrate produces steam. After receiving steam, the user can inhale the steam through the second end 136 of the substrate holder 114. In some scenarios, the user may be aware that it takes a certain amount of time for the aerosol generating device 100 to heat the aerosol generating substrate 128 to a first temperature and for the aerosol generating substrate 128 to begin producing steam. This means that the user can decide when to start inhaling the steam. In other scenarios, the aerosol generating device 100 is configured to provide an indication to the user that the vapor is available for inhalation. Moreover, in the first embodiment, the control circuit 122 causes

- 18 043642 illumination of the user-activated button 116 when the aerosol-forming substrate 128 is at a first temperature for an initial period of time. In another embodiment, the indication is provided by another indicator, for example by generating an audible sound or vibration of the vibrating mechanism. Likewise, in other embodiments, the indication is provided after a fixed period of time after activation of the aerosol generating device 100, once the heater 124 reaches operating temperature, or due to some other event.

The user may continue to inhale the vapor for as long as the aerosol-forming substrate 128 can continue to produce steam, for example, for as long as the aerosol-forming substrate 128 has vaporizable components remaining to evaporate to form a suitable vapor. The control circuit 122 regulates the power supplied to the heater 124 to ensure that the temperature of the aerosol-forming substrate 128 does not exceed a threshold level. In particular, at a certain temperature, which depends on the composition of the aerosol-forming substrate 128, the aerosol-forming substrate 128 will begin to burn. This effect is undesirable and temperatures equal to or above this temperature must be avoided. To facilitate this, the aerosol generating device 100 is provided with a temperature sensor (not shown). The control circuit 122 is configured to receive an indication from the temperature sensor of the temperature of the aerosol-forming substrate 128 and use that indication to control power supplied to the heater 124. For example, in one scenario, the control circuit 122 supplies maximum power to the heater 124 for an initial period of time. until the heater or chamber reaches the first temperature. Then, after the aerosol-forming substrate 128 reaches a first temperature, the control circuit 122 stops supplying power to the heater 124 for a second period of time until the aerosol-forming substrate 128 reaches a second temperature below the first temperature. Then, after the heater 124 reaches a second temperature, the control circuit 122 begins to supply power to the heater 124 for a third period of time until the heater 124 next reaches the first temperature. This may continue until the aerosol generating substrate 128 is consumed (ie, all the aerosol that could have been generated by heating has already been generated) or until the user stops using the aerosol generating device 100. In another scenario, after reaching the first temperature, control circuit 122 reduces power to heater 124 to maintain aerosol-forming substrate 128 at the first temperature without increasing the temperature of aerosol-forming substrate 128.

The user's single breath is commonly referred to as a puff. In some scenarios, it is desired to simulate the experience of smoking cigarettes, which means that the aerosol generating device 100 is typically configured to contain enough aerosol generating substrate 128 to provide ten to fifteen puffs.

In some embodiments, the control circuit 122 is configured to count puffs and turn off the heater 124 after the user has completed ten to fifteen puffs. Counting puffs is done in one of many different ways. In some embodiments, control circuit 122 senses when the temperature during a puff decreases as fresh cool air flows past temperature sensor 170, causing cooling that is detected by the temperature sensor. In other embodiments, air flow is detected directly using a flow sensor. Other suitable methods will be apparent to one skilled in the art. In other embodiments, the control circuit additionally or alternatively turns off the heater 124 after a predetermined amount of time has elapsed since the first puff. This can help both reduce power consumption and provide a reserve for shutdown if the puff counter fails to correctly register the receipt of a predetermined number of puffs.

In some examples, the control circuit 122 is configured to power the heater 124 so that it follows a predetermined heating cycle requiring a predetermined amount of time to complete. Once this cycle is completed, heater 124 is completely turned off. In some cases, this loop may utilize a feedback loop between heater 124 and a temperature sensor (not shown). For example, the heating cycle can be parameterized by a range of temperatures to which the heater 124 (or more accurately, the temperature sensor) is heated or allowed to cool. To optimize the temperature of the aerosol-forming substrate 128, the temperature and duration of such a heating cycle can be determined empirically. This may be necessary because directly measuring the temperature of the aerosol-forming substrate may be impractical or misleading, such as when the outer layer of the aerosol-forming substrate 128 is at a different temperature than the core.

In the following example, the time for the first puff is 20 seconds. After this point, the power level supplied to the heater 124 is reduced from 100% so that the temperature remains constant at approximately 240°C for a period of approximately 20 seconds. Heating power

- 19 043642 valve 124 can then be further reduced so that the temperature detected by temperature sensor 170 is approximately 200°C. This temperature can be maintained for approximately 60 seconds. The power level can then be further reduced such that the temperature sensed by temperature sensor 170 drops to the operating temperature of substrate holder 114, which in this case is approximately 180°C. This temperature can be maintained for 140 seconds. This period of time may be determined by the length of time during which the substrate holder 114 can be used. For example, substrate holder 114 may stop producing aerosol after a predetermined period of time, so the period of time during which the temperature is set to 180°C may allow the heating cycle to continue for that duration. After this point, the power supplied to the heater 124 may be reduced to zero. Even after the heater 124 is turned off, the aerosol or vapor generated while the heater 124 was turned on can still be drawn out of the aerosol generating device 100 when sucked by the user. Therefore, even when the heater 124 is turned off, the user may be alerted to this situation by a visible indicator remaining on despite the fact that the heater 124 has already been turned off in preparation for ending the aerosol inhalation session. In some embodiments, this predetermined period may be 20 seconds. The total heating cycle time in some embodiments may be approximately 4 minutes.

The above described exemplary heating cycle can be modified by the user's use of a substrate holder 114. When the user withdraws the aerosol from the substrate holder 114, the user's inhalation entrains cool air through the open end of the heating chamber 108 towards the base 112 of the heating chamber 108, flowing past the heater 124. The air may then enter the substrate holder 114 through the tip 134 of the substrate holder 114. The entry of cold air into the cavity of the heating chamber 108 reduces the temperature measured by the temperature sensor 170 as the cold air replaces the hot air that was previously present therein. When the temperature sensor 170 detects that the temperature has decreased, this can be used to increase the power supplied by the battery to the heater to heat the temperature sensor 170 back to the operating temperature of the substrate holder 114. This can be achieved by applying a maximum amount of power to the heater 124 or, alternatively, by applying an amount of power greater than the amount necessary to maintain a steady-state temperature reading by the temperature sensor 170.

The power supply 120 is sufficient to at least bring the aerosol-forming substrate 128 in one substrate holder 114 to a first temperature and maintain it at the first temperature to provide an amount of vapor sufficient for at least ten to fifteen puffs. In general, consistent with simulating the cigarette smoking experience, the power supply 120 is typically sufficient to repeat this cycle (bringing the aerosol-forming substrate 128 to a first temperature, maintaining the first temperature, and generating steam for ten to fifteen puffs) ten times or even twenty times, thereby simulating the user's experience of smoking a pack of cigarettes before the power supply 120 needs to be replaced or recharged.

In general, the efficiency of the aerosol generating device 100 is increased when as much heat generated by the heater 124 heats the aerosol generating substrate 128 as possible. To this end, the aerosol generating device 100 is typically configured to controllably apply heat to the aerosol generating substrate 128 while reducing heat flow to other portions of the aerosol generating device 100. In particular, the heat flow to the parts of the aerosol generating device 100 operated by the user is maintained at a minimum level, thereby keeping those parts cool and comfortable to hold, for example by using insulation, as described in more detail in the present invention.

From fig. 1-6 and the accompanying description, it is understood that according to the first embodiment, a heating chamber 108 is provided for the aerosol generating device 100, wherein the heating chamber 108 includes an open end 110, a base 112, and a side wall 126 between the open end 110 and the base 112, wherein side wall 126 has a first thickness, and base 112 has a second thickness greater than the first thickness. The reduced thickness of the side wall 126 can help reduce the power consumption of the aerosol generating device 100 because it requires less energy to heat the heating chamber 108 to the required temperature.

Second embodiment.

The second embodiment is described below with reference to FIG. 8. The aerosol generating device 100 according to the second embodiment is identical to the aerosol generating device 100 according to the first embodiment described with reference to FIG. 1-6, except as described below, and like reference numerals are used to refer to like elements. The aerosol generating device 100 according to the second embodiment is arranged to allow air to be drawn into the heating chamber 108 during use,

- 20 043642 which is different from the layout according to the first embodiment.

In more detail, with reference to Fig. 8, a channel 113 is provided in the base 112 of the heating chamber 108. The channel 113 is located in the center of the base 112. It extends through the base 112 so that it is in fluid communication with the environment outside the outer shell 102 of the aerosol generating device 100. More specifically, channel 113 is in fluid communication with inlet 137 in outer shell 102.

The inlet 137 extends through the outer shell 102. It is located at a distance along the length of the outer shell 102 between the first end 104 and the second end 106 of the aerosol generating device 100. In a second embodiment, the outer shell defines a cavity 139 in the vicinity of the control circuit 122, between the inlet 137 in the outer shell 102 and the channel 113 in the base 112 of the heating chamber 108. The cavity 139 provides fluid communication between the inlet 137 and the channel 113 so that air may flow from the environment outside the outer shell 102 into the heating chamber 108 through the inlet 137, cavity 139, and channel 113.

In use, as the user inhales steam at the second end 136 of the substrate holder 114, air is drawn into the heating chamber 108 from the environment surrounding the aerosol generating device 100. More specifically, air passes through the inlet 139 in the direction of arrow C into the cavity 139. From the cavity 139, the air passes through the channel 113 in the direction of arrow D into the heating chamber 108. This allows steam first and then steam mixed with air to be drawn through a substrate holder 114 in the direction of arrow D for user inhalation at the second end 136 of the substrate holder 114. As air enters the heating chamber 108, it generally becomes heated, and thus the air assists in transferring heat to the aerosol-forming substrate 128 by convection.

It is understood that in the second embodiment, the path for air flow through the heating chamber 108 is generally linear, that is, the path extends from the base 112 of the heating chamber 108 to the open end 110 of the heating chamber 108, broadly speaking, in a straight line. The arrangement according to the second embodiment also makes it possible to reduce the gap between the side wall 126 of the heating chamber 108 and the substrate holder. Moreover, in the second embodiment, the diameter of the heating chamber 108 is less than 7.6 mm, and the gap between the 7.0 mm diameter substrate holder 114 and the side wall 126 of the heating chamber 108 is less than 1 mm.

In variations of the second embodiment, the inlet 137 is located differently. In one particular embodiment, the inlet 137 is located at the first end 104 of the aerosol generating device 100. This allows air to flow broadly straight through the entire aerosol generating device 100, such as air entering the aerosol generating device 100 at the first end 104, which is typically oriented distally relative to the user during use, flowing through the substrate 128 forming aerosol (or over the substrate, past the substrate, etc.), into the aerosol generating device 100, and therefrom into the user's mouth at the second end 136 of the substrate holder 114, which is typically oriented proximally relative to the user during use, e.g., in the mouth user.

Third embodiment.

The third embodiment is described below with reference to FIG. 9, 9(a) and (b). These figures show a heating chamber 108 that is identical to the heating chamber 108 according to the first embodiment described with reference to FIGS. 1-6, except as described below, and like reference numerals are used to refer to like elements. It is also possible that the heating chamber 108 according to the third embodiment corresponds to the heating chamber 108 according to the second embodiment, for example, with a channel 113 provided in the base 112 of the heating chamber 108, except as described below, and this constitutes a further embodiment of the invention.

Heating chamber 108 according to a third (and additional) embodiment has a flange 138 that is thicker than side wall 126.

As noted above, the effect provided by the flange 138 is to provide strength to the heating chamber 108, in particular to enable the side wall 126 to resist deformation or buckling. By making the flange 138 thicker than the side wall 126, the resistance to buckling or warping is increased. The thickness of the flange 138 from about two to five times the thickness of the side wall 126 or alternatively up to about 0.4 mm is a suitable thickness range. There is little benefit to making the flange 138 thicker than specified when the side wall 126 has a thickness within the thickness range described above with respect to the first embodiment, since the flange 138 of this thickness is already much stronger than the side wall 126. this leaves a thin wall as the weakest point for failure. Increasing the thickness of the flange 138 increases the heat capacity of the heating chamber 108. Therefore, there is a need to balance the thickness of the flange so as not to increase

- 21 043642 The heat capacity of the heating chamber is excessive.

Fourth embodiment.

The fourth embodiment is described below with reference to FIG. 10, 10(a) and (b). These figures show a heating chamber 108 that is identical to the heating chamber 108 according to the first embodiment described with reference to FIGS. 1-6, except as described below, and like reference numerals are used to refer to like elements. It is also possible that the heating chamber 108 according to the fourth embodiment corresponds to the heating chamber 108 according to the second embodiment, for example with a channel 113 provided in the base 112 of the heating chamber 108, except as described below, and this constitutes a further embodiment of the present invention.

The heating chamber 108 according to the fourth (and further) embodiment has a flange 138 that forms an acute angle with the side wall 126.

The flange 138 tapers outward from the open end 110 in a direction away from the base 112 of the heating chamber 108. In the illustrated version of the fourth embodiment, the flange 138 extends at an angle of approximately 45° relative to the side wall 126. In other versions of the fourth embodiment, the flange 138 extends at a different angle, typically from 30 to 60° relative to the side wall 126. The flange 138 is shaped like a truncated cone, with the smaller round end of the truncated cone aligned with the edge of the side wall 126 at the open end 110 of the heating chamber 108. In practice, the heating chamber 108 can be described as having the shape of a funnel, wherein the flange 138 is a cone and the side wall 126 is a neck.

Fifth embodiment.

A fifth embodiment is described below with reference to FIG. 11, 11(a) and (b). These figures show a heating chamber 108 that is identical to the heating chamber 108 according to the first embodiment described with reference to FIGS. 1-6, except as described below, and like reference numerals are used to refer to like elements. It is also possible that the heating chamber 108 according to the fifth embodiment corresponds to the heating chamber 108 according to the second embodiment, for example with a channel 113 provided in the base 112 of the heating chamber 108, except as described below, and this constitutes a further embodiment of the present invention.

The heating chamber 108 according to the fifth (and additional) embodiment has a flange 138 formed as a separate piece relative to the side wall 126.

In a fifth embodiment, the flange 138 is a separate component relative to the side wall 126 that is attached to the open end 110 of the heating chamber 108, for example, through screw threads, soft soldering, brazing, adhesives, interference fits, or through multi-layer molding, for example, plastic material at the open end 110 of the heating chamber 108. It should be noted that forming the flange 138 as a separate piece allows the flange 138 to be manufactured from a different material. In some cases, the material may have increased strength relative to the material from which the side wall 126 is formed, meaning that less material can be used to form the flange 138, thus keeping the heat capacity of the heating chamber 108 low without sacrificing strength. In other examples, flange 138 may be formed from a material having a lower thermal conductivity than the material from which the heating chamber is formed.

108 thus reduce thermal conductivity from the heating chamber 108 and improve the efficiency of the device.

In some examples, the flange 138 may have a width equal to the width of the bottom washer 107b (see, for example, FIG. 2), and be placed in the outer shell 102. In this case, there is no need for the bottom washer 107b, since the flange 138 serves as a reinforcement element and installation tool.

Sixth embodiment.

The sixth embodiment is described below with reference to FIG. 12. The aerosol generating device 100 according to the sixth embodiment is identical to the aerosol generating device 100 according to the first embodiment described with reference to FIG. 1-6, except as described below, and like reference numerals are used to refer to like elements. It is also possible that the heating chamber 108 according to the sixth embodiment corresponds to the heating chamber 108 according to the second embodiment, for example, with a channel 113 provided in the base 112 of the heating chamber 108, except as described below, and this constitutes a further embodiment of the present invention.

The aerosol generating device 100 of the sixth (and further) embodiment has a heating chamber 108 having a flange 138 that is located in a recess in the washers 107a and 107b.

More specifically, the lower washer 107b has a recess in its upper surface that helps ensure proper seating of the heating chamber 108 in the outer shell 102.

- 22 043642

Seventh embodiment.

The seventh embodiment is described below with reference to FIG. 13. The aerosol generating device 100 according to the seventh embodiment is identical to the aerosol generating device 100 according to the first embodiment described with reference to FIG. 1-6, except as described below, and like reference numerals are used to refer to like elements. It is also possible that the heating chamber 108 according to the seventh embodiment corresponds to the heating chamber 108 according to the second embodiment, for example, with a channel 113 provided in the base 112 of the heating chamber 108, except as described below, and this constitutes a further embodiment of the present invention.

The aerosol generating device 100 of the seventh (and further) embodiment has a heating chamber 108 having an acutely angled flange 138 that is positioned in a recess in the washers 107a and 107b.

Similar to the sixth embodiment, this provides a means by which the heating chamber 108 can be held securely and in the correct position while the recess is shaped to receive a flange 138 at an acute angle.

Definitions and alternative embodiments.

From the above description it is clear that many features of the various embodiments are interchangeable. The present invention extends to additional embodiments including features from different embodiments combined with each other in ways not specifically mentioned. For example, embodiments three through five do not have the platform 148 shown in FIG. 1-6. Platform 148 may be included in embodiments three through five, thereby benefiting from platform 148 described in relation to these figures.

In fig. 9-11 show a heating chamber 108 separated from the aerosol generating device 100. This is presented to emphasize that the advantageous features described for the design of the heating chamber 108 are independent of other features of the aerosol generating device 100. For example, the flange features set forth in embodiments three through seven may be different from the rest of the invention. In particular, the heating chamber 108 has many uses, not all of which are related to the aerosol generating device 100 described in the present invention. Such designs may require a thin side wall 126 and yet a robust arrangement, such as that provided by the flange 138. Such applications are advantageously proposed in conjunction with the heating chamber described in the present invention.

The term heater should be understood to mean any device for outputting thermal energy sufficient to generate an aerosol from the aerosol-forming substrate 128. The transfer of thermal energy from heater 124 to aerosol-forming substrate 128 may be conductive, convective, radiant, or any combination of these methods. By way of non-limiting examples, conductive heaters may directly contact and compress the aerosol-forming substrate 128, or may contact a separate component that itself causes heating of the aerosol-forming substrate 128 by conduction, convection, and/or radiation. Convective heating may involve heating a liquid or gas, which then (directly or indirectly) transfers thermal energy to the substrate, forming an aerosol.

Radiant heating includes, but is not limited to, transferring energy into the aerosol-forming substrate 128 by emitting electromagnetic radiation in the ultraviolet, visible, infrared, microwave, or radio frequency portions of the electromagnetic spectrum. The radiation thus emitted may be absorbed directly by the aerosol-forming substrate 128, causing heating, or the radiation may be absorbed by another material, such as a detector or fluorescent material, resulting in the radiation being re-emitted at a different wavelength or spectral weighting. In some cases, radiation may be absorbed by the material, which then transfers heat to the aerosol-forming substrate 128 through any combination of conduction, convection, and/or radiation.

The heater may be electrically powered, combustion powered, or any other suitable means. Electric heaters may include resistive track elements (optionally containing insulating padding), induction heating systems (eg, containing an electromagnet and a high-frequency oscillator), etc. The heater 128 may be located around the outside of the aerosol-forming substrate 128, it may partially or completely penetrate the aerosol-forming substrate 128, or any combination thereof.

The term temperature sensor is used to describe an element configured to determine the absolute or relative temperature of a portion of the aerosol generating device 100. It may include thermocouples, thermocouples, thermistors, etc. The temperature sensor may be provided as part of another component, or it may be a separate component. In some examples, more than one temperature sensor may be provided, e.g.

- 23 043642 for monitoring the heating of various parts of the aerosol generating device 100, for example to determine temperature profiles.

The control circuit 122 has been shown throughout to have a single user-operated button 116 for activating the aerosol generating device 100. This maintains ease of operation and reduces the chances of the user misusing the aerosol generating device 100 or misoperating the aerosol generating device 100. In some cases, however, the input controls available to the user may be more complex than those specified, such as for controlling the temperature, such as within preset limits, such as changing the flavor balance of the steam, or switching between energy saving and fast heat modes.

With reference to the above-described embodiments, the aerosol-forming substrate 128 contains tobacco, for example in a dried or fermented form, in some cases with additional ingredients to flavor or provide a more uniform or otherwise more enjoyable experience. In some examples, the aerosol-forming substrate 128, such as tobacco, may be treated with a vaporizer. The evaporation promoting agent may improve the generation of vapor from the aerosol-forming substrate. The evaporative agent may contain, for example, a polyol such as glycerin or a glycol such as propylene glycol. In some cases, the aerosol-forming substrate may not contain tobacco or even contain nicotine, but instead may contain natural or artificially produced ingredients to flavor, impart volatility, enhance uniformity, and/or provide other pleasurable effects. The aerosol-forming substrate 128 may be provided as a solid or paste type material in cut, briquetted, powder, granular, strip or sheet form, optionally a combination of these forms. Equally, the aerosol-forming substrate 128 may be a liquid or a gel. Moreover, some examples may contain both solid and liquid/gel parts.

Therefore, the aerosol generating device 100 may equally be referred to as a heated tobacco device, a non-burning tobacco heating device, a tobacco product evaporation device, and the like, and should be interpreted as a device suitable for achieving these effects. The features described in the present invention are equally applicable to devices configured to vaporize any aerosol-forming substrate.

Embodiments of the aerosol generating device 100 are described as being configured to receive an aerosol generating substrate 128 in a pre-packaged substrate holder 114. The substrate holder 114 may be broadly similar to a cigarette and have a tubular region with the aerosol-forming substrate suitably positioned. Some designs may also include filters, vapor collection areas, cooling areas, and other structures. A layer of paper or other flexible flat material such as foil may also be provided, for example to hold the aerosol-forming substrate in place, to further resemble a cigarette, etc.

For purposes of the present invention, the term fluid should be construed to generally describe non-solid materials of the type that are capable of flowing, including, but not limited to, liquids, pastes, gels, powders and the like. Accordingly, the term fluidized materials should be interpreted to mean materials that are essentially fluids or have been modified to behave like fluids. Fluidization may include, but is not limited to, pulverization, dissolution in a solvent, gelation, thickening, dilution, and the like.

As used herein, the term volatile means a substance capable of readily changing from a solid or liquid state to a gaseous state. By way of non-limiting example, a volatile substance may be a substance having a boiling or sublimation point near room temperature at atmospheric pressure. Accordingly, the terms volatilize or volatilize should be interpreted to mean making (a material) volatile and/or causing evaporation or dispersion in a vapor.

As used herein, the term vapor (or vapor) means: (i) the form into which liquids are naturally converted when exposed to a sufficient degree of heat; or (ii) particles of liquid/moisture suspended in the atmosphere and visible as clouds of vapor/smoke; or (iii) a fluid that fills a volume like a gas, but, having a temperature below its critical temperature, can be converted into a liquid by pressure alone.

For purposes of this definition, the term vaporize (or convert to vapor) means: (i) to change or cause a change to vapor; and (ii) change the physical state of the particles (i.e., from liquid or solid to gaseous state).

As used herein, the term atomize (or dust) means: (i) to reduce (a substance, in particular a liquid) into very small particles or droplets; and (ii) maintain the particles in the same physical state (liquid or solid) as before atomization.

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Claims (17)

As used herein, the term aerosol means a system of particles dispersed in air or gas, such as fog, mist or smoke. Accordingly, the term aerosolize (or aerosolize) means to aerosolize and/or disperse as an aerosol. It should be noted that the meaning of the term aerosolize/form an aerosol is consistent with each of the terms volatile, atomize, and evaporate defined above. To avoid confusion, the term aerosol is used to consistently describe a mist or droplet containing atomized, volatilized or evaporated particles. The term aerosol also includes mist or droplets containing any combination of atomized, volatilized or vaporized particles. CLAIM 1. A heating chamber (108) for an aerosol generating device (100), wherein the heating chamber (108) contains: a first washer (107a) and a second washer (107b); a tubular side wall (126) having an open first end (110); and a flange portion (138) at the open first end (110) of the tubular side wall (126), the flange portion extending radially outward from the tubular side wall (126); wherein the flange portion (138) is sandwiched between the first washer (107a) and the second washer (107b), wherein the tubular side wall (126) and the flange portion (138) are made of metal or alloy, and the first and second washers are formed of heat-insulating material. 2. Heating chamber (108) according to claim 1, characterized in that the first and second washers are formed from polyetheretherketone (PEEK). 3. Heating chamber (108) according to claim 1 or 2, characterized in that the heating chamber (108) passes through the central opening of the second washer (107b). 4. Heating chamber (108) according to any of the previous paragraphs, characterized in that the flange part (138) is located in a recess in the second washer (107b). 5. Heating chamber (108) according to any of the previous paragraphs, characterized in that the flange portion (138) extends completely around the heating chamber (108). 6. Heating chamber (108) according to any of the previous paragraphs, characterized in that the flange portion (138) extends obliquely from the tubular side wall (126). 7. Heating chamber (108) according to any of the previous claims, characterized in that the tubular side wall (126) has a thickness of 90 μm or less. 8. Heating chamber (108) according to any of the previous claims, characterized in that it further has a base (112) at the second end of the tubular side wall (126) opposite the open first end (110). 9. Heating chamber (108) according to any one of the previous claims, characterized in that the tubular side wall (126) and the flange portion (138) contain the specified metal or alloy, preferably the metal is stainless steel, even more preferably the metal is stainless steel 300 grade stainless steel, even more preferably the metal is selected as one of 304 grade stainless steel, 316 grade stainless steel and 321 grade stainless steel. 10. Heating chamber (108) according to any of the previous claims, characterized in that the heating chamber (108) contains a material having a thermal conductivity of 50 W/m-K or less. 11. The heating chamber (108) as claimed in any one of the preceding claims, wherein the flange portion (138) contains a first material and the tubular side wall (126) contains a second material, wherein the first material has a lower thermal conductivity than the second material. 12. Heating chamber (108) according to any of the previous claims, characterized in that the heating chamber (108) is at least partially manufactured by deep drawing. 13. Device (100) generating an aerosol, containing: power source (120); heating chamber (108) according to any one of claims 1 to 12; a heater (124) configured to supply heat to the heating chamber (108); and a control circuit (122) configured to control the supply of power from the power source (120) to the heater (124). 14. The aerosol generating device (100) according to claim 13, characterized in that the heating chamber (108) is attached to the aerosol generating device (100) by means of a flange portion (138), wherein preferably the flange portion (138) is located between two parts of the aerosol generating device (100) to attach the heating chamber (108) to the aerosol generating device (100). 15. The aerosol generating device (100) according to claim 13 or 14, characterized in that the heater (124) is provided on the outer surface of the tubular side wall (126). 16. The aerosol generating device (100) according to claim 15, characterized in that the heater (124) is located adjacent to the outer surface of the tubular side wall (126). 17. An aerosol generating device (100) according to any one of claims 13 to 16, characterized in that: -