Aerosol generating device having a heated chamber with a thermal guard - Patents.com

Abstract

A heating chamber (108) for an aerosol generating device (100) is provided. The aerosol generating device (100) has a heater (124) disposed externally of the heating chamber (108), and the heating chamber (108) is arranged to receive an elongated substrate carrier (114), the elongated substrate carrier (114) having an aerosol substrate (128) disposed toward a first end (134) of the elongated substrate carrier (114). The heating chamber (108) includes a tubular sidewall (126) defining an interior volume and an open first end (110) through which the substrate carrier (114) can be received within the interior volume and through which air can flow toward the aerosol substrate (128). A contact surface (168) exposed to the interior volume is provided for contacting the substrate carrier (114) at or near the second end of the interior volume. The heating chamber further includes a second end (111) distal to the open first end (110). A heating region (164) is provided through which heat from an externally disposed heater (124) is applied to the heating chamber (108). The heating chamber also includes a thermal guard (166) at the second end (111) for preventing heat flow from the heating region (164) to the at least one contact surface (168).

Description

[Technical field]

[0001] The present disclosure relates to an aerosol generating device having a heating chamber with a thermal guard. The disclosure is particularly applicable to portable aerosol generating devices that may be self-contained and low temperature. Such devices can heat tobacco or other suitable materials by conduction, convection and / or radiation, rather than by combustion, to generate an aerosol for inhalation. [Background technology]

[0002] The popularity and use of reduced or modified risk smoking devices (also known as vaporizers) has grown rapidly in recent years as an aid to assist regular smokers wishing to quit smoking traditional tobacco products such as cigarettes, cigars, cigarillos and rolling cigarettes. A variety of devices and systems are available that heat or warm an aerosolizable substance, as opposed to burning tobacco in traditional tobacco products.

[0003] A commonly available reduced or modified risk smoking device is a substrate heated aerosol generating device or a heated non-combustion device. This type of device generates an aerosol or vapor by heating an aerosol substrate, which typically includes moist tobacco or other suitable aerosolizable material, to a temperature typically ranging from 150°C to 300°C. By heating, rather than burning or combusting, the aerosol substrate, an aerosol is released that includes the ingredients desired by the user, but does not include the toxic and carcinogenic by-products of combustion and burning. Furthermore, aerosols generated by heating tobacco or other aerosolizable material typically do not include the burnt or bitter taste that can result from combustion and burning, which can be unpleasant to the user. Thus, the substrate does not require sugars and other additives that are typically added to such materials to make the smoke and / or vapor more palatable to the user.

[0004] It is generally desirable to rapidly heat the aerosol substrate to a temperature at which an aerosol can be released from the aerosol substrate, and to maintain the aerosol substrate at that temperature. It will be apparent that the aerosol can be released from the aerosol substrate and delivered to a user only if there is air flow past the aerosol substrate. Summary of the Invention [Problem to be solved by the invention]

[0005] Because this type of aerosol generating device is a portable device, energy consumption is an important design consideration. Ensuring that the generated heat is delivered to specific portions of the aerosolizable material and inhibiting heat flow to other portions can help improve efficiency and provide correct operation. The present disclosure aims to address the problems with existing devices and to provide an improved aerosol generating device and heating chamber therefor. [Means for solving the problem]

[0006] According to a first aspect of the present disclosure, there is provided a heating chamber for an aerosol generating device, the aerosol generating device having a heater disposed externally to the heating chamber, the heating chamber for receiving an elongated substrate carrier, the elongated substrate carrier having an aerosol substrate disposed toward a first end of the elongated substrate carrier, and the heating chamber defining an internal volume and including: a tubular sidewall having a first end, through which the elongated substrate carrier can be received within the internal volume and through which air can flow toward the aerosol substrate, and a second end distal to the first end; a heating region, through which heat from the externally disposed heater is applied to the heating chamber; a contact surface exposed to the internal volume for contacting the substrate carrier at or near the second end of the internal volume; and a thermal guard at the second end for preventing heat flow from the heating region to at least one contact surface.

[0007] Heat from an externally disposed heater is transferred to the interior volume through the tubular sidewall in the heating region. More specifically, heat is transferred from the externally disposed heater radially through the tubular sidewall to the interior volume by conduction. Heat can be transferred directly from the tubular sidewall to the aerosol substrate and / or indirectly from the tubular sidewall to the aerosol substrate by heating air flowing from the first end toward the aerosol substrate.

[0008] This configuration reduces exposure of the tip of the substrate carrier to excessive temperatures from the heater by blocking heat flow to the contact surface (e.g., by blocking a conductive flow path between the heater and the contact surface), thereby reducing unwanted generation of aerosol from the tip. The tubular sidewall may have a dimension, e.g., a diameter, that is greater than a dimension, e.g., a diameter, of the elongated substrate carrier at the location of the contact surface. Thus, at the location of the contact surface, there is no contact between the tubular sidewall and the elongated substrate carrier, which means that no heat is transferred by conduction directly from the tubular sidewall to the tip of the substrate carrier, thereby avoiding direct heating of the tip.

[0009] The second end may be closed such that air is drawn exclusively through the first end toward the aerosol substrate, more specifically, between the outer layer of the elongated substrate carrier and the tubular side wall toward the aerosol substrate.

[0010] The aerosol generating device may include one or more heaters disposed externally to a heating chamber. The heating chamber may include one or more of said heating zones through which heat from a corresponding one of said one or more externally disposed heaters is applied to the heating chamber. The thermal guard may be configured to block heat flow from each heating zone to at least one of the contact surfaces.

[0011] Optionally, the at least one contact surface faces the first end of the tubular sidewall.

[0012] Optionally, the thermal guard comprises a first material and the tubular sidewall comprises a second material, the first material having a lower thermal conductivity than the second material. In particular, the thermal guard may be made of ceramic or a heat resistant plastic such as PEEK. The tubular sidewall may be made of a metal such as stainless steel or copper.

[0013] Optionally, at least one contact surface is a surface of a thermal guard.

[0014] Optionally, the thermal guard is annular.

[0015] Optionally, the thermal guard is a separate element attached to the tubular sidewall.

[0016] Optionally, the contact surface extends from the tubular sidewall into the interior volume.

[0017] Optionally, the heating chamber further comprises a base at a second end of the tubular sidewall.

[0018] Optionally, the heating region comprises a portion of the base.

[0019] Optionally, the heating region includes a portion of the tubular sidewall.

[0020] Optionally, the thermal guard includes a portion of the base.

[0021] Optionally, the thermal guard extends inwardly from the base towards the interior volume to provide a seat for supporting the substrate carrier.

[0022] Optionally, the thermal guard extends across the entire width of the base.

[0023] Optionally, the thermal guard is a separate element attached to the base.

[0024] Optionally, the heating chamber further includes an insert including a thermal guard, the insert positioned for removable insertion into the interior volume of the heating chamber.

[0025] Optionally, the insert may include a mesh or wire netting.

[0026] Optionally, the insert may include a plurality of rod-shaped elements.

[0027] According to a second aspect of the present disclosure, there is provided an aerosol generating device comprising the above-mentioned heating chamber and a heater, wherein the heater is attached to a tubular side wall and the heating region is defined by an area of ​​the tubular side wall which is at least partially overlapped by the heater.

[0028] Optionally, the heater is attached to a surface of the tubular sidewall facing away from the interior volume.

[0029] Optionally, the aerosol generating device further comprises a power supply and a control circuit configured to control the supply of power from the power supply to the heater.

[0030] Optionally, the aerosol generating device further comprises a spacer for holding the substrate carrier in a central configuration within the heating chamber.

[0031] Optionally, the spacer is removably coupled to the aerosol generating device.

[0032] According to a third aspect of the present disclosure, there is provided an aerosol generation system comprising an aerosol generation device as described above and a substrate carrier.

[0033] According to a fourth aspect of the present disclosure, there is provided an insert for a heating chamber for the above-mentioned aerosol generating device, the insert including a thermal guard for preventing heat flow from a heating region of the heating chamber to at least one contact surface, the insert being dimensioned to be inserted into an inner surface of the heating chamber to prevent heat flow from the heating region to at least one contact surface.

[0034] Optionally, the insert includes a mesh or wire netting or a plurality of bar-shaped elements configured to retain the thermal guard at a distal end of the insert. [Brief description of the drawings]

[0035] [Figure 1] FIG. 1 is a schematic perspective view of an aerosol generating device according to a first embodiment of the present disclosure, in which the aerosol generating device is loaded with a substrate carrier for an aerosol substrate. [Diagram 2] FIG. 2 is a schematic cross-sectional side view of the aerosol generating device of FIG. 1, in which the aerosol generating device is loaded with a substrate carrier of an aerosol substrate. [Diagram 3] FIG. 2 is a schematic perspective view of the aerosol generating device of FIG. 1, in which the aerosol generating device is loaded with a substrate carrier of an aerosol substrate. [Figure 4] FIG. 2 is a schematic cross-sectional side view of the aerosol generating device of FIG. 1, in which the aerosol generating device is loaded with a substrate carrier for the aerosol substrate. [Diagram 5] 5 is a detailed cross-sectional view of a portion of FIG. 4 highlighting the interaction between the substrate carrier and protrusions within the heating chamber and the corresponding effect on the air flow path. [Figure 6A] 2 is a schematic cross-sectional side view of the heating chamber of the aerosol generating device of FIG. 1. [Figure 6B] FIG. 6B is a schematic perspective cutaway view of the heating chamber shown in FIG. 6A. [Figure 7] A schematic cross-sectional side view of an aerosol generating device according to a second embodiment similar to the first embodiment, but with an alternative airflow configuration. [Figure 8A] 11 is a schematic cross-sectional side view of a heating chamber according to a third embodiment in which a thermal guard is disposed on a base. [Figure 8B] FIG. 8B is a schematic perspective cutaway view of the heating chamber shown in FIG. 8A. [Figure 8C] 1 is a schematic cross-sectional view of an aerosol generating device having a heating chamber according to a third embodiment, including a spacer. [Figure 9] FIG. 13 shows a schematic perspective view of a heating chamber according to a fourth embodiment having side walls and a base formed by rods. [Figure 10] FIG. 13 shows a schematic perspective view of a heating chamber according to a fifth embodiment having side walls formed of a mesh material or wire netting. [Figure 11] 13 shows a schematic cross-sectional view of a heating chamber according to a sixth embodiment, in which the thermal guard is flush with the remainder of the base. [Figure 12] 13 shows a schematic cross-sectional view of a heating chamber according to a seventh embodiment having a thermal guard that extends across the base of the heating chamber. [Figure 13A] 13 shows a schematic cross-sectional view of a heating chamber according to an eighth embodiment, in which the base of the heating chamber includes a shelf portion on which a thermal guard sits within the interior volume of the heating chamber. [Figure 13B] FIG. 13B shows a bottom perspective view of the heating chamber shown in FIG. 13A. [Figure 14] A schematic cross-sectional view of a heating chamber according to a ninth embodiment is shown, having a thermal guard located in a central position above the base of the heating chamber and a contact surface coupled to the upper surface of the thermal guard. [Figure 15] A schematic cross-sectional view of a heating chamber according to a tenth embodiment is shown, having a thermal guard bonded to a tubular side wall of the heating chamber, with a contact surface bonded to a surface of the thermal guard facing the open first end of the heating chamber. [Figure 16] A schematic cross-sectional view of a heating chamber according to an eleventh embodiment is shown, having a thermal guard positioned in a recess between tubular side walls forming a base and at the lower end of the heating chamber. [Figure 17] A schematic cross-sectional view of a heating chamber according to a twelfth embodiment is shown in which the base includes a recess that does not pass entirely through the base, within which is a thermal guard that is flush with the inner surface of the remainder of the base. [Figure 18A] A schematic cross-sectional view of a heating chamber according to a thirteenth embodiment is shown, comprising a proximal section of a tubular side wall, a distal section of the tubular side wall, and an annular section of a thermal guard positioned between the proximal and distal sections of the tubular side wall to join the proximal and distal sections together and prevent heat exchange between the two sections. [Figure 18B] FIG. 18B is a schematic perspective cutaway view of the heating chamber shown in FIG. 18A. [Figure 19A] FIG. 23 shows a schematic perspective view of an insert according to a fourteenth embodiment having side walls and a base formed by a rod. [Figure 19B] 14 shows a schematic cross-sectional view of an insert according to a fourteenth embodiment being inserted into a heating chamber. [Figure 19C] A schematic cross-sectional view of an insert according to a fourteenth embodiment inserted into a heating chamber and a substrate carrier inserted into the insert is shown. [Figure 19D] FIG. 19D is a schematic cross-sectional view of an aerosol generating device having the insert of FIG. 19C and a heating chamber. [Figure 19E] A schematic cross-sectional view of an aerosol generating device similar to Figure 19D, including a spacer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] First embodiment 1-6B, according to a first embodiment of the present disclosure, an aerosol generating device 100 includes an outer casing 102 that houses various components of the aerosol generating device 100. In the first embodiment, the outer casing 102 has an irregular shape, but it will be understood that any shape is possible as long as it is sized to fit the components described in the various embodiments shown herein.

[0037] The first end 104 of the aerosol generating device 100 shown at the bottom of each of Figures 1-6 is described for convenience as the bottom, base or lower end of the aerosol generating device 100. The second end 106 of the aerosol generating device 100 shown at the top of each of Figures 1-6 is described as the top or upper end of the aerosol generating device 100. During use, a user typically orients the aerosol generating device 100 with the first end 104 facing downward and / or in a distal position relative to the user's mouth and the second end 106 facing upward and / or in a proximal position relative to the user's mouth.

[0038] The aerosol generating device 100 has a heating chamber 108 located towards 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. In other words, the heating chamber 108 has an open first end 110 towards the second end 106 of the aerosol generating device 100. The heating chamber 108 is kept spaced apart from the inner surface of the outer casing 102 to prevent heat flow into the outer casing 102. To increase the thermal insulation of the heating chamber 108, the heating chamber 108 may further be surrounded by an insulator, for example a fibrous or foam material such as cotton wool, aerogel or gas, or in other examples a vacuum insulator may be provided.

[0039] The heating chamber 108 is arranged to receive a substrate carrier 114, also known as a "consumable," as shown in FIGS. 1-5. Typically, the substrate carrier 114 includes a prepackaged aerosol substrate 128, such as tobacco or another suitable aerosolizable material, provided with an aerosol collection region 130. Both the aerosol substrate 128 and the aerosol collection region 130 are encased in an outer layer 132 and abut one another at a boundary midway along the substrate carrier 114. The aerosol substrate 128, which is heatable to generate an aerosol for inhalation, is located toward a first end 134 (or "tip") of the substrate carrier 114. The aerosol substrate 128 extends across the entire width of the substrate carrier 114 within the outer layer 132. In other embodiments, the heating chamber 108 is configured to receive other forms of aerosol substrate 128, such as loose cut material or otherwise packaged solid material.

[0040] The heating chamber 108 has a sidewall 126 that extends between a base 112 (located at the second end 111 of the heating chamber) and an open first end 110. The sidewall 126 and the base 112 are connected to one another. In some embodiments, the sidewall 126 and the base 112 are formed as a single piece. In a first embodiment, the sidewall 126 is tubular. More specifically, the sidewall is circular, cylindrical. However, in other embodiments, the sidewall 126 has other suitable shapes, such as a tube having an elliptical or polygonal cross section. In yet another embodiment, the sidewall 126 is tapered.

[0041] In a first embodiment, the base 112 of the heating chamber 108 is closed, e.g., sealed or airtight. That is, the heating chamber 108 is cup-shaped. This ensures that air drawn in from the open first end 110 is prevented by the base 112 from exiting the second end, but is instead guided through the aerosol substrate. This also allows a user to insert the substrate carrier 114 into the heating chamber 108 to an intended distance and not beyond.

[0042] The heater 124 is mounted on the exterior surface of the heating chamber 108. That is, the heater 124 is mounted on the surface of the tubular sidewall 126 that faces away from the interior volume of the heating chamber 108. This may help protect the heater 124 from damage when the substrate carrier 114 is inserted into the heating chamber 108. The heater 124 is typically electrically powered. In a first embodiment, the heater 124 is a film heater that includes conductive (e.g., metal) tracks superimposed on a flexible, electrically insulating backing material (such as polyimide).

[0043] In a first embodiment, the aerosol generating device 100 is electrically powered, i.e. it is configured to heat the aerosol substrate 128 using electrical power. For this purpose, the aerosol generating device 100 comprises a power source 120, e.g. a battery. The power source 120 is coupled to a control circuit 122. The control circuit 122 is in turn coupled to a heater 124. A user operates the aerosol generating device 100 using control means (not shown) configured to couple the power source 120 to the heater 124 and to decouple the power source 120 from the heater 124 via the control circuit 122.

[0044] The footprint of the heater 124 defines the heating region 164. In other words, the heating region 164 is the portion of the tubular sidewall 126 to which heat from the heater 124 is applied to heat the heating chamber 108 (and thereby provide heat to the aerosol substrate 128). In other embodiments, the heating region 164 is the portion of the sidewall 126 that is heated by a heat source, such as an induction heater, a radiant heater, or even a heater that operates by burning a fuel. The heating region 164 is shown in the drawings (see, for example, FIGS. 6A and 6B) as a cylindrical portion of the sidewall 126, but is optionally axially and / or circumferentially intermittent along or around the sidewall 126. It should be noted that the heat does not stop at the heating region 164, but spreads entirely through the tubular sidewall 126 due to the effect of conduction. The heating region 164 is the region where heat is transferred radially (through the sidewall 108) to the heating chamber 108. Longitudinal heat transfer along the tubular sidewall 126 can be reduced by reducing the thickness of the sidewall 126 as much as possible (e.g., 100 μm or less). However, it cannot be completely eliminated. A discontinuous configuration can be provided by arranging the conductive heating tracks so as to overlap areas that are part of the heating area 164 and not overlap areas that are not intended to be part of the heating area 164. If induction heating is used, the heating area 164 can be differentiated from other parts of the sidewall 126 by including in the heating area 164 a material (e.g., a magnetic material) that has a particularly strong response to induction heating and using a material that has a weaker response (or indeed little or no response) in other parts of the sidewall 126. Similarly, with respect to embodiments of radiant or combustive heating, a radiant or combustive jet (e.g., a flame) can be induced in a particular area (or areas) of the sidewall 126. Such areas define the heating area 164. Optionally, the heating region 164 may also be or include a portion or the entirety of the base 112 .

[0045] Generally, the heating chamber 108 includes a thermal guard 166. The thermal guard 166 may be part of the chamber or may be added to the chamber as a permanent or removable part (e.g., as part of a removable insert). In a first embodiment, the thermal guard 166 is a disk of thermally insulating material provided as a separate element attached to the base 112. Preferably, the thermal guard 166 includes a material (e.g., a thermally insulating material) that is different from the material used to form the tubular sidewall 126, specifically a material that has a lower thermal conductivity than the material of the tubular sidewall 126. This prevents conductive heat flow through the thermal guard 166. Because the thermal guard 166 is located between the heating area 164 and the contact surface 168, the thermal guard 166 prevents conductive heat flow from the heating area 164 to the contact surface 168.

[0046] As shown in Fig. 5, the contact surface 168 faces the open first end 110 of the tubular side wall 126. In a first embodiment, the contact surface 168 is the surface of the thermal guard 166 that faces away from the base 112, for example upwards or towards the inner volume of the heating chamber 108. As shown, this configuration means that the contact surface 168 is the surface that the tip 134 of the substrate carrier 114 comes into contact with when the substrate carrier 114 is inserted into the heating chamber 108. Such a positioning of the contact surface 168 ensures in a simple manner that conductive heat flow from the heating area 164 to the tip 134 of the substrate carrier 114 is prevented. It can be clearly seen that the thermal guard 166 prevents conductive heat flow from the heating area to the contact surface 168. That is, with the tip 134 resting on the contact surface 168, conductive heat flow from the heating region 164 to the tip 134 is prevented or blocked by the thermal guard 166, so that conductive heating must occur by transfer through the thermal guard 166, which is a thermal insulating element as described above. The center of the tip 134 is also protected from excess hot air entering the airflow path. Thus, overheating of the tip 134 is prevented. At the same time, the contact surface 168 is sized to leave an uncovered (e.g., annular) portion of the tip 134 so that air can flow through the gap between the sidewall 126 and the substrate carrier 114 at the tip 134 to the aerosol substrate 128 (arrow B in FIG. 5 ).

[0047] The thermal guard 166 may comprise any material that can withstand deformation due to forces associated with contact of the tip 134 of the substrate carrier 114 as it is inserted into the heating chamber 108, and can also withstand repeated heating by the heater 124 to a temperature of about 200° C. Suitable materials include ceramics, such as machinable glass ceramics, and other suitable materials, such as high temperature plastics. In some cases, polymers such as polyetheretherketone (PEEK), with an upper operating temperature of up to 250° C., may be used. It should be noted that further embodiments described below allow for different configurations of the thermal guard 166, but the above considerations regarding thermal and mechanical stability and suitable materials apply to all embodiments.

[0048] The sidewall 126 has a thickness that is significantly less than the length of the heating chamber 108. This means that because the sidewall 126 is so thin, heat transfer through the sidewall 126 encounters negligible resistance. However, heat transfer along the sidewall 126 (i.e. parallel to the central axis or around the periphery of the sidewall 126) has small channels through which conduction can occur, so that the heat generated by the heater 124 (located on the outer surface of the heating chamber 108 in this example) remains localized near the heater 124 but rapidly causes heating of the inner surface of the heating chamber 108. This can help to reduce heat transfer from the heater 124 to the base 112. In addition, the thin sidewall 126 helps to reduce the thermal mass of the heating chamber 108, which in turn improves the overall efficiency of the aerosol generating device 100, because less energy is used to heat the sidewall 126.

[0049] To further improve the localization of heat, the heating chamber 108, and specifically the sidewall 126 of the heating chamber 108, comprises a material having a thermal conductivity of 50 W / mK or less. In a first embodiment, the heating chamber 108 is a metal, preferably stainless steel. Stainless steel has a thermal conductivity of about 15 W / mK to 40 W / mK, with the exact value depending on the specific alloy. As a further example, 300 series stainless steel suitable for this application has a thermal conductivity of about 16 W / mK. Suitable examples include 304, 316 and 321 stainless steels, which are approved for medical applications, have high strength and have a sufficiently low thermal conductivity to allow for the localization of heat described herein. In general, metals are suitable materials because they are strong, malleable, and easy to mold and form. In addition, their thermal properties vary widely from metal to metal and can be tailored by careful alloying as needed. In this disclosure, "metal" refers to elemental (i.e. pure) metals as well as alloys with two or more metals or other elements, such as carbon. It should be noted that in the illustrated embodiment, base 112 is thicker than sidewall 126, e.g., between 2 and 10 times thicker than sidewall 126. In some cases, this may result in base 112 that is between 200 μm and 500 μm thick, e.g., about 400 μm thick, which may help provide support to sidewall 126 and strengthen sidewall 126 against backing or other damage.

[0050] The sidewall 126 may be provided with a number of protrusions 140 that extend into the volume defined by the sidewall 126. The width of the protrusions 140 around the periphery of the sidewall 126 is less than its length parallel to the central axis of the sidewall 126 (or generally in the direction of the first end 110 open from the base 112 of the heating chamber 108). Four is a preferred number of protrusions 140 to hold the substrate carrier 114 in a central position within the heating chamber 108, although other numbers may be used. When the substrate carrier 114 is inserted into the heating chamber 108, the protrusions 140 extend toward and engage the substrate carrier 114. The protrusions provide and maintain a controlled gap for an air flow path (arrow B) between the inner surface of the heating chamber 108 (between adjacent protrusions 140) and the substrate carrier 114. The protrusions 140 are formed by deforming or indenting the sidewall 126, which has the advantage that the protrusions 140 are integral with the sidewall 126 and therefore have a minimal effect on heat flow. Furthermore, the protrusions 140 so formed do not add thermal mass, as would be the case if additional elements were added to the inner surface of the sidewall 126 of the heating chamber 108. Finally, indenting the sidewall 126 as described increases the strength of the sidewall 126 by introducing transversely extending portions thereto.

[0051] The aerosol generating device 100 functions by both thermal conduction from the surfaces of the protrusions 140 that engage the outer layer 132 of the substrate carrier 114 and by convection heating, in which air in the air gap between the inner surface of the sidewall 126 and the outer surface of the substrate carrier 114 is heated and drawn through the substrate carrier 114.

[0052] It will be apparent that the surface 145 of each protrusion 140 engages the outer layer 132 of the substrate carrier 114 to conduct heat into the aerosol substrate 128. To mitigate the effects of any variations in the diameter of the substrate carrier 114 due to manufacturing tolerances, damage, or shrinkage due to heating and drying, the protrusions 140 are preferably dimensioned to extend far enough into the heating chamber 108 to create a compression of the substrate carrier 114. This further ensures an interference fit between the surface 145 of each protrusion 140 and the outer layer 132 of the substrate carrier 114. This compression of the outer layer 132 of the substrate carrier 114 may also result in better heat conduction within the aerosol substrate 128 by squeezing air out of the aerosol substrate 128.

[0053] 5 shows a close-up view of the heating chamber 108 and the substrate carrier 114. As can be seen, arrow B indicates the air flow path that provides the convection heating described above. Air flows down the side of the substrate carrier 114 (before and after the protrusions 140) to enter the tip 134. The air flow path occupies the equally spaced interstitial areas between the four protrusions 140.

[0054] The space bounded by adjacent protrusions 140, sidewall 126 and outer layer 132 of substrate carrier 114 defines the area available for airflow. The smaller this space, the harder the user must inhale to draw air into the aerosol generating device 100 (known as increased resistance to inhalation). The size, number and spacing of protrusions 140 can be adjusted to provide a satisfactory resistance to inhalation that is neither too low nor too high, and allows for a balance between conductive and convective heating. The heating chamber 108 can be made larger to increase the airflow channel between the sidewall 126 and substrate carrier 114, but there is a practical limit to this before the gap becomes too large and the heater 124 begins to become ineffective. Typically, a gap of 0.2 mm to 0.3 mm around the outer surface of substrate carrier 114 is a good compromise, allowing the resistance to inhalation to be fine-tuned within tolerances by varying the dimensions of protrusions 140.

[0055] The portion of the sidewall 126 that is heated (heated area 164) may generally correspond to the location of the protrusions 140 (or a slightly larger area of ​​the sidewall 126), so that the heat generated is conducted by the protrusions 140 to the substrate carrier 114, while the thin sidewall 126 prevents the heat from being conducted along the tubular sidewall 126 toward the open first end 110 and base 112. The open first end 110 and base 112 experience a smaller temperature increase upon heating than the protrusions, in part because the open first end 110 and base 112 do not receive the heat directly (e.g., they are located away from the heated area 164) and also because of the smaller longitudinal conduction force provided by the thin sidewall 126. At other locations, e.g., between adjacent protrusions 140, air is heated and convectively heats the aerosol substrate 128.

[0056] Optionally, further localization of heating may be provided by a thermally conductive layer (e.g., a thin layer of metal such as copper (not shown)) between the heater 124 and the heating chamber 108. In such a case, the heating area 164 may be defined as the area covered by the thermally conductive layer, which may be larger than the heater 124 alone. Such a thermally conductive layer may further improve thermal contact between the heater 124 and the heating chamber 108 and also serve to conduct heat to the protrusions 140. It will be appreciated that the thermally conductive layer may be used in conjunction with other heating means (combustion, radiation, induction heating, etc.) to define the heating area 164 where heat received from a heat source is "spread" over the extent of the thermally conductive layer.

[0057] When a user wishes to use the aerosol generating device 100, the user first loads the substrate carrier 114 into the heating chamber 108 by inserting the substrate carrier 114 into the heating chamber 108. The substrate carrier 114 is inserted into the heating chamber 108 with a first end or tip 134 of the substrate carrier 114 oriented to enter the heating chamber 108 first such that the aerosol substrate 128 is located adjacent the base 112 with the tip 134 in contact with the contact surface 168. The substrate carrier 114 is inserted into the heating chamber 108 until the tip 134 of the substrate carrier 114 rests on the base 112 of the heating chamber 108. In this embodiment, there is an additional effect of the interaction between the upper edge 142 of the protrusion 140 and the interface between the aerosol substrate 128 and the adjacent aerosol collection region 130 of the low compressibility substrate carrier 114, which notifies the user that the substrate carrier 114 has been inserted sufficiently deep into the aerosol generating device 100.

[0058] 3 and 4, it can be seen that when the substrate carrier 114 is inserted as deeply as possible into the heating chamber 108, only a portion of the length of the substrate carrier 114 is inside the heating chamber 108. The remainder of the length of the substrate carrier 114 protrudes from the heating chamber 108. At least a portion of the remainder of the length of the substrate carrier 114 also protrudes from the second end 106 of the aerosol generating device 100 and can be used as a mouthpiece through which a user draws aerosol by suction from the aerosol substrate 128. In other embodiments, all or substantially all of the substrate carrier 114 can be contained within the aerosol generating device 100 such that no portion, or substantially no portion, of the substrate carrier 114 protrudes from the aerosol generating device 100.

[0059] The thermal guard 166 provides a support platform above the base 112 of the heating chamber 108 such that the length of the aerosol substrate 128 (between the tip 134 and the aerosol collection area 130) approximately matches the distance between the top edge 142 of the projection 140 (closest to the open first end 110 of the heating chamber 108) and the contact surface 168. In another embodiment, the distance between the top edge 142 of the projection 140 and the top of the thermal guard 166 is slightly less than the length of the aerosol substrate 128. This means that the tip 134 of the substrate carrier 114 extends slightly past the top of the thermal guard 166, causing compression of the aerosol substrate 128 at the tip 134 of the substrate carrier 114. Thus, the thermal guard 166 can be partially inserted into the substrate carrier 114 by compression of the aerosol substrate 128, but the tip 134 does not touch the inner surface of the base 112 to ensure that the thermal guard 166 prevents conductive heat flow from the base 112 to the aerosol substrate 128.

[0060] There is an annular region around the thermal guard 166 that provides an air flow passage from the gap between the inner surface of the sidewall 126 (near and between adjacent protrusions 140) and the outer layer 132 of the substrate carrier 114 to the tip 134 of the substrate carrier 114. This effect can be achieved by the thermal guard 166 extending at least about 1 mm higher than the remainder of the base 112 (towards the open first end 110 of the heating chamber 108).

[0061] In use, when a user switches on the aerosol generating device 100, power from the power supply 120 is provided via (and under the control of) the control circuit 122 to the heater 124. The heater 124 transfers heat to the aerosol substrate 128 via the heating region 164, heating the aerosol substrate 128 to a temperature at which it can begin to emit vapor or aerosol. Additionally, convective heating of the aerosol substrate 128 occurs as described above.

[0062] Once heated to a temperature at which the aerosol can begin to be released, a user can inhale the aerosol by drawing the aerosol through the second end 136 of the substrate carrier 114. That is, the aerosol originates from the aerosol substrate 128 located at the first end 134 of the substrate carrier 114 within the heating chamber 108, is drawn along the length of the substrate carrier 114, through the aerosol collection region 130 within the substrate carrier 114, and to the second end 136 of the substrate carrier where it enters the user's mouth. This flow of aerosol is indicated by arrow A in FIG. 4.

[0063] It will be appreciated that when a user inhales the aerosol in the direction of arrow A in Figure 4, the aerosol flows from adjacent the aerosol substrate 128 in the heating chamber 108. This action draws ambient air into the heating chamber 108 through the first end 110 of the aerosol generating device 100 that is open from the ambient environment (via the flow path indicated by arrow B in Figures 4 and 5). This ambient air flows into the space provided between the sidewall 126 of the heating chamber 108 and the outer layer 132 of the substrate support 114, where it is heated by the heater 124. The heated air then heats the aerosol substrate 128, generating an aerosol as the heated air is drawn through the aerosol substrate 128.

[0064] The user can continue to inhale the aerosol as long as the aerosol substrate 128 continues to generate aerosol (e.g., as long as the aerosol substrate 128 has remaining vaporizable components to vaporize into a suitable aerosol and is maintained at a suitable temperature. The control circuit 122 adjusts the power supplied to the heater 124 to prevent the temperature of the aerosol substrate 128 from exceeding a threshold level, e.g., the temperature at which the aerosol substrate 128 begins to burn.

[0065] Although the heating chamber 108 above has been described in relation to a heating chamber 108 housed within an aerosol generating device 100, the example shown in Figures 6A and 6B illustrates that the present disclosure extends to a heating chamber 108 alone. Indeed, although shown in Figures 6A and 6B as having a heater 124 on an exterior surface of the heating chamber 108, the present disclosure extends to a heating chamber 108 lacking such a heater 124 and having only a heating region 164 for receiving heat from a heat source.

[0066] Here, the alternative embodiments will be described by showing only the heating chamber 108. By analogy with Figures 6A and 6B of the first embodiment, the heating chamber 108 of any of the following embodiments can replace the heating chamber 108 shown in the aerosol generating device 100 of Figures 1-4, and the operation of the aerosol generating device is substantially the same as above.

[0067] Second embodiment Referring to Figure 7, 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 Figures 1 to 6, except as described below, and the same reference numbers are used to refer to similar features.

[0068] The aerosol generating device 100 of the second embodiment has a configuration that allows air to be drawn into the heating chamber 108 during use, which differs from the first embodiment.

[0069] More specifically, an air flow passage or channel 113 is provided in the base 112 of the heating chamber 108. In a second embodiment, the channel 113 is centrally located in the base 112. The channel 113 extends through the base 112 such that it is in fluid communication with the environment outside the heating chamber 108. In other embodiments, the channel 113 is provided in another location in the base 112, multiple channels are provided in the base 112, one or more channels are provided in the sidewall 126 adjacent the base 112, or portions of the base 112 and / or sidewall 126 are perforated.

[0070] An inlet 137 is provided through the outer casing 102. The inlet 137 is configured to be in fluid communication with the channel 113. In the second embodiment, the inlet 137 is located midway along the length of the outer casing 102 between the first end 104 and the second end 106 of the aerosol generating device 100. The outer casing 102 also defines a gap 139 between the inlet 137 in the outer casing 102 and the channel 113 in the base 112 of the heating chamber 108. The gap 139 provides fluid communication between the inlet 137 and the channel 113, such that air can be delivered from the environment outside the outer casing 102 through the inlet 137, the gap 139 and the channel 113 to the heating chamber 108. In other words, the air flow passage 113 traverses the base 112.

[0071] In use, air is drawn from the environment surrounding the aerosol generating device 100 into the heating chamber 108 as a user inhales aerosol at the second end 136 of the substrate carrier 114. More specifically, air passes through the inlet 137 in the direction of arrow C and enters the gap 139. From the gap 139, the air passes through the channel 113 in the direction of arrow D and enters the heating chamber 108. This allows first the aerosol, and then the aerosol mixed with the air, to be drawn through the substrate carrier 114 in the direction of arrow D and inhaled by the user at the second end 136 of the substrate carrier 114.

[0072] The thermal guard 166 also has openings (aligned with the channels 113 in the base 112) through which air enters the interior of the heating chamber 108. That is, in this example, the air flow passage also traverses the thermal guard 166. In the example shown, the air drawn in at arrows C and D is fresh air from the outside, meaning that it has not been heated to a degree that would allow it to generate aerosols as it passes through the aerosol substrate 128. Heating is primarily achieved conductively by the heater 124 and the heating area 164. However, because of the presence of the protrusions 140 in this embodiment, there is an air gap between the inner surface of the heating chamber 108 (between the protrusions) and the outer layer 132 of the substrate carrier 114. This means that convection heating can also occur in the manner described above. In other examples, this air gap need not be present and the aerosol substrate 128 can be heated by conduction while cool fresh air is drawn in through alternative air flow paths shown as arrows C and D in FIG. 7.

[0073] This configuration decouples conductive heating (through the protrusions 140) from the resistance to draw discussion discussed above with respect to the first embodiment. In other words, since the air flow path is no longer affected by the protrusions 140, but instead penetrates the base 112 of the heating chamber, the area of ​​the contact surface of the protrusions 140 can be freely selected without considering the effect on resistance to draw. Although the heater 124 heats the heating area 164 and the protrusions 140 to provide heat to the aerosol substrate 128 through the outer layer 132 of the substrate carrier, the effect of preventing overheating of the tip 134 by the thermal guard 166 still exists in that conductive heat transfer to the contact surface 168 (and from there to the tip 134) is blocked by the presence of the thermal insulating thermal guard 166. In some cases, the air may be heated as it enters the heating chamber 108, which aids in transferring heat to the aerosol substrate 128 by convection.

[0074] In variations of the second embodiment, the inlet 137 is in a different location. In one particular embodiment, the inlet 137 is located at the first end 104 of the aerosol generating device 100. This allows the air passage through the entire aerosol generating device 100 to be generally linear, e.g., air enters the aerosol generating device 100 at the first end 104, which is typically oriented distal to a user during use, flows through (or over, through, etc.) the aerosol substrate 128 within the aerosol generating device 100, and enters the user's mouth at the second end 136 of the substrate carrier 114, which is typically oriented proximal to the user during use, e.g., toward the user's mouth.

[0075] Third embodiment 8A and 8B, the heating chamber 108 according to the third embodiment is identical to the heating chamber 108 of the first embodiment described with reference to Figures 1-6B, except as described below, and the same reference numbers are used to refer to similar features. The configuration of the third embodiment is very similar to that shown in Figures 6A and 6B, except that the protrusions 140 are not present in Figures 8A and 8B. The thermal guard 166 blocks the flow of heat from the heating region to the contact surface 168 in the same manner as described above.

[0076] In this embodiment, the heating chamber 108 contacts the substrate carrier 114 around its periphery and can still provide conductive heating by using air flow passages as in the second embodiment. In a further example, the heating chamber 108 can be non-circular in cross section (e.g., oval, square, etc.) and contact the substrate carrier 114 around a portion of its periphery to provide conductive heating and compression.

[0077] In yet another example, the gap between the heating chamber and the substrate carrier can be obtained by a spacer disposed above at or near the open first end 110 of the heating chamber 108. In yet another example, the heating can be entirely convective, and there can be no contact at all between the sidewall 126 and the outer surface 132 of the substrate carrier 114. As shown in FIG. 8C, in the absence of the protrusion 140, an exemplary spacer 190 can be provided above the open first end 110 of the heating chamber 108 to enable the substrate carrier 114 to be held centrally within the heating chamber 108. In other words, the substrate carrier 114 is spaced from the inner surface of the sidewall 126, leaving an annular air gap between the outer surface 132 of the substrate carrier and the tubular sidewall 126. That is, the spacer 190 can hold the substrate carrier 114 in a central configuration within the heating chamber 108.

[0078] In the illustrated embodiment, the spacer 190 has an annular cross-section through which the substrate carrier 114 can be inserted and is snugly held. The spacer 190 includes holes to allow airflow through the heating chamber (as shown by arrows B). Alternatively, the spacer 190 may not extend completely around the periphery of the substrate carrier 114, but may be of interrupted annular cross-section or formed with discrete protrusions that hold the substrate carrier centered within the heating chamber 108.

[0079] Other configurations of the spacer 190 may allow air to be drawn through the spacer 190 while maintaining the substrate carrier 114 within the heating chamber 108, for example the spacer 190 may have one or more gaps, or one or more gaps where the spacer 190 does not contact the substrate carrier 114 inserted therethrough, through which air may be drawn during use. In general, the spacer 190 may be suitable for use with air flow paths corresponding to either the first or second embodiment described above. It will be appreciated that embodiments of the spacer 190 may form a seal around the substrate carrier 114 when inserted, preventing air from being drawn through the open first end 110 of the heating chamber during use. Such a configuration corresponds to the heating chamber 108 according to the second embodiment described above, where air enters the device through the inlet 137 and passes to the heating chamber 108 through the channel 113 in the base 112.

[0080] The spacer 190 is shown flush with the outer casing 102 at the second end 106 of the aerosol generating device 100. In some embodiments, the spacer 190 may be recessed, for example, into the aerosol generating device 100, such that the outer casing protects the spacer 190 from damage.

[0081] In this embodiment, the spacer 190 is permanently fixed within the aerosol generating device 100, but may be removable (in other words, the spacer 190 may be or may be removably coupled to the aerosol generating device 100), for example, the spacer 190 may be clipped onto the outer body 102 of the aerosol generating device 100. In such an embodiment, the spacer 190 may be attached to the substrate carrier 114 before both are introduced into the aerosol generating device 100, such that the tip 134 of the substrate carrier 114 rests on the contact surface 168 and the spacer 190 is clipped into place, as shown in FIG. 8C. Attaching the spacer 190 to the substrate carrier 114 before inserting it into the heating chamber 108 may allow a user to carefully monitor the attachment process, thereby reducing the possibility of damage to the substrate carrier 114. Furthermore, a user may verify by visual inspection that the spacer 190 has been correctly attached onto the substrate carrier 114.

[0082] While embodiments having spacers 190 are particularly useful in embodiments without protrusions 140, they may also be used in embodiments having protrusions 140 or other portions that contact the substrate support 114 and hold it in place within the heating chamber 108. For example, the spacers 190 may provide additional support (in addition to the protrusions 140 or other contacting portions) for centering the substrate support 114 and may also help retain heat inside the heating chamber 108 by partially blocking the open first end 110 to reduce the flow of heated air out of the heating chamber 108.

[0083] Fourth embodiment Referring to FIG. 9, the heating chamber 108 of the fourth embodiment is similar to (and operates similarly to) the heating chamber 108 of the first embodiment described with reference to FIGS. 1-6B, except as described below, and the same reference numbers are used to refer to like features.

[0084] The sidewall 126 of the heating chamber 108 in FIG. 9 includes a plurality of rod-shaped elements 176. In the illustrated example, the rods 176 are bent toward the central axis at the second end 111 of the heating chamber 108 to form a base, but this is optional and in some cases the base may be solid, similar to the previous embodiment. In yet another example, the tubular sidewall 126 may be solid and the base is formed of rods. The base of the heating chamber 108 shown in FIG. 9 includes a thermal guard 166 having an upwardly facing contact surface 168. A heating region 164 is shown midway along the rods 176.

[0085] Additionally, the heating chamber 108 is configured to receive the elongated substrate carrier 114 in a manner similar to the previous embodiment. The heating chamber 108 is shown with a rim 107 coupled to the proximal end of the heating chamber 108. This is an optional feature shown in FIG. 9, but helps protect the rod from damage, e.g., bending, by allowing the upper end of the rod to be secured within the rim 107. The heating chamber 108 may be configured, for example, by providing a heater (such as heater 124 in FIGS. 1-5) around the outside of the heating chamber 108 in the heating region 164, such that the heating region 124 of the tubular side wall 126 directly heats the heating chamber 108 or the elongated substrate carrier 114. The embodiment shown in FIG. 9 allows for a reduced heat flow path to the contact surface 168 compared to a solid wall having a thickness equal to the diameter of the rod 176.

[0086] The rod-like elements 176 can be thought of as solid sidewalls 126 (see, for example, FIGS. 6A and 6B) with some portions removed to form openings, leaving the rods 176 as shown. Of course, the heating chamber 108 need not be formed by removing wall sections to leave the rods 176, but may preferably be formed by combining a series of appropriately shaped rods 176 and joining them together to form the structure shown in FIG. 9. The effect of the resulting structure is to remove some of the conductive heat transfer channels relative to the solid sidewalls while allowing a larger air gap to allow for convective heat transfer. In other words, although the thermal guard 166 has an increased thermal resistivity compared to the material from which the sidewalls 126 (or the elongated rods 176) are made, the geometry of the heating chamber 108 shown in FIG. 9 is such that the thermal resistance in the vertical direction is increased (compared to the solid sidewalls 126). This is because the heat transfer channels are reduced (assuming the elongated rods have the same thickness as the tubular sidewalls 126).

[0087] The rod 176 may be configured to perform substantially the same function as the protrusion 140 of the first and second embodiments, providing compression of the aerosol substrate 128 and maintaining good thermal contact with the substrate carrier 114 even when the aerosol substrate 128 shrinks when heated and dried.

[0088] Fifth embodiment Referring to FIG. 10, the heating chamber 108 of the fifth embodiment is similar to (and operates similarly to) the heating chamber 108 of the first embodiment described with reference to FIGS. 1-6B, except as described below, and the same reference numbers are used to refer to like features.

[0089] Heating chamber 108 is similar to that of Figure 9, except that sidewalls 126 and base are made of mesh 180 rather than bar elements 176 of Figure 9. In some embodiments, heating chamber 108 may include both mesh 180 and bar elements. In other examples, the base may be formed of a solid material and only sidewalls 126 are formed of mesh (or vice versa). Heating region 164 is shown midway along sidewall 126.

[0090] Heating chamber 108 is shown having a rim 107 coupled to the proximal end of heating chamber 108. This serves to protect the upper edge of mesh 180 from damage.

[0091] The heating chamber 108 may be configured such that the heating region 124 of the tubular sidewall 126 directly heats the heating chamber 108 or the elongated substrate support 114. The embodiment shown in Figure 10 allows for a reduced heat flow path to the first end 134 of the elongated substrate support 114. The embodiment of Figure 10 may be configured such that the base of the heating chamber 108 has a thermal guard 166 disposed within the heating chamber 108 and having a contact surface 168 provided by an upper surface of the thermal guard 166.

[0092] Similar to the description of the fourth embodiment above, the mesh 180 resembles a solid sidewall with a portion removed and can therefore be considered to have a reduced conductive heat transfer channel compared to the solid sidewall 126, thereby reducing the conductive heat transfer channel from the heating area 164 to the contact surface. This has the effect of increasing the thermal resistance compared to the solid tubular sidewall 126. Thus, the mesh sidewall 126 prevents conductive heat flow along the wall to the base. The thermal insulating thermal guard 166, which blocks conductive heat transfer to the tip 134, further prevents heat conducted to the base 112 from causing overheating of the tip 134.

[0093] Because the mesh 180 is air permeable, it can also help improve airflow and reduce draw resistance, allowing greater design freedom in this regard.

[0094] 9 and 10, thermal resistance can be increased by selectively thinning all or portions of the sidewall 126 or by selectively forming holes in the sidewall 126. Each of these approaches to increasing thermal resistance can be applied to the solid tubular sidewall 126 designs described herein.

[0095] Sixth embodiment Referring to FIG. 11, the heating chamber 108 of the sixth embodiment is similar to (and operates similarly to) the heating chamber 108 of the first embodiment described with reference to FIGS. 1-6B, except as described below, and the same reference numbers are used to refer to like features.

[0096] The distal end 111 of the heating chamber includes a base portion 112. The base portion 112 is formed as a unitary piece with the sidewall 126 and extends radially inwardly from the sidewall 126 but does not completely close the distal end 111, leaving a central opening.

[0097] The opening is blocked by a thermal guard 166, with the distal end 111 closed. The thermal guard has a contact surface 168 shaped and sized to have an area at least as large as the cross-sectional area of ​​the substrate carrier 114. This means that the tip 134 can fit completely within the contact surface 168. The thermal guard 166 therefore blocks heat flow from the heating region 164 partway along the tubular sidewall 126 to the contact surface 168. In the embodiment of FIG. 11, the thermal guard is flush with the base 112 of the heating chamber 108. In other examples, the thermal guard 166 may extend towards the open first end 110 and thus not be flush with the base 112, but rather form a pedestal. In this latter example, the thermal guard 166 may not have a contact surface 168 sized to have an area at least as large as the cross-sectional area of ​​the substrate carrier 114, resulting instead in a configuration similar to that shown in the first embodiment.

[0098] The openings in the base portion 112 reduce the thermal mass of the heating chamber 108 (compared to a full base such as the first embodiment), thereby increasing the efficiency of providing heat to the heating chamber 108 .

[0099] Seventh embodiment With reference to FIG. 12, the heating chamber 108 of the seventh embodiment is similar to (and operates similarly to) the heating chamber 108 of the first embodiment described with reference to FIGS. 1-6B, except as described below, and the same reference numbers are used to refer to like features.

[0100] The base 112 is integrally formed with the tubular sidewall 126 at the second end 111 of the sidewall 126. In this embodiment, there are no holes in the base 112. The thermal guard 166 is coupled to the base such that it is disposed above the base 112 in the heating chamber 108 and such that the thermal guard 166 extends across the entire base. The thermal guard 166 has a contact surface 168 such that the first end 134 of the elongated substrate contacts the contact surface 168 when fully inserted into the heating chamber 108. Configuring the thermal guard 166 to extend across the entire base 112 ensures that even if the substrate carrier is not correctly inserted (i.e., coaxially with the tubular wall 126) and is off-center, the tip 134 will still contact the contact surface 168, thus preventing a conductive heat flow path from the heating region 164 to the tip 134.

[0101] Eighth embodiment 13A and 13B, the heating chamber 108 according to the eighth embodiment is similar to (and operates similarly to) the heating chamber 108 of the first embodiment described with reference to Figures 1-6B, except as described below, and the same reference numbers are used to refer to like features. Figure 13A shows a cross-sectional view of the heating chamber 108 of this embodiment, and Figure 13B shows a perspective view of the heating chamber 108 from below, cut open to show the interior of the heating chamber 108.

[0102] The distal end 111 of the heating chamber includes a base portion 112. The base portion 112 is formed as an integral part with the sidewall and extends radially inward from the sidewall, but does not completely close the distal end 111, leaving a central opening. In other words, the base portion 112 forms a shelf with a hole in the center of the heating chamber 108. In the illustrated embodiment, a thermal guard 166 is supported by the shelf formed by the base portion 112. The thermal guard has a contact surface 168, which is the surface facing the open first end 110. In use, when the first end of the elongated substrate carrier 114 is fully inserted into the heating chamber, the first end 134 contacts the contact surface 168 of the thermal guard 166.

[0103] The construction of the heating chamber 108 according to the eighth embodiment may be simpler than the other embodiments because the thermal guard 166 may be cut to size and pressed into the bottom portion 111 where it is held by friction or an interference fit. Additionally, the openings in the base portion 112 reduce the thermal mass of the heating chamber 108 (compared to the seventh embodiment), thereby improving the efficiency of providing heat to the heating chamber 108.

[0104] Ninth embodiment With reference to FIG. 14, the heating chamber 108 of the ninth embodiment is similar to (and operates similarly to) the heating chamber 108 of the first embodiment described with reference to FIGS. 1-6B, except as described below, and the same reference numbers are used to refer to like features.

[0105] A thermal guard 166 is coupled to the heat chamber base 112 at the distal second end 111. A contact surface 168 is coupled to the thermal guard 166 at the distal second end 111 of the heat chamber such that the contact surface 168 is located closer to the open first end 110 than the thermal guard.

[0106] The contact surface 168 is configured such that when the elongated substrate carrier 114 is fully inserted into the heating chamber 108, the first end 134 of the elongated substrate carrier contacts the contact surface 168. The thermal guard 166 is formed of a thermally insulating material. The thermal guard prevents heat flow between the heating region 164 and the contact surface 168 because heat flow from the heating region 164 must be conducted down the sidewall 126 and then through the thermal guard 166 to reach the tip 134 of the substrate carrier 114.

[0107] Whereas in the previous embodiment the top surface of the thermal guard 166 was the contact surface 168, in this embodiment the thermal guard 166 and the contact surface 168 are separate from each other. This means that the contact surface 168 can be made of a different material than the thermal guard 166. This can mean that each element can be made of the material best suited for the task. Furthermore, the interface between the thermal guard 166 and the contact surface 168 can introduce an additional insulating effect due to the thermal resistance of the interface. Thus, if the contact surface 168 is made of a separate layer from the thermal guard 166, the thermal guard 166 can be made of a cheaper or in some embodiments less thermally resistant material.

[0108] Tenth embodiment Referring to FIG. 15, the heating chamber 108 of the tenth embodiment is similar to (and operates similarly to) the heating chamber 108 of the first embodiment described with reference to FIGS. 1-6B, except as described below, and the same reference numbers are used to refer to like features.

[0109] The thermal guard 166 of the tenth embodiment is a separate annular element that is attached to and extends radially inward from the tubular sidewall 126. A heating region 164 is located on the tubular sidewall 126 midway between the two ends 110, 111.

[0110] In this embodiment, the thermal guard 166 extends into the interior volume perpendicular to the tubular sidewall 126. In a related embodiment, the thermal guard 166 may be formed with any number of protrusions, separate or coupled together, that protrude inwardly from the tubular sidewall 126 of the heating chamber 108.

[0111] The thermal guard 166 has a separate layer that forms a contact surface 168 and faces the open first end 110 of the heating chamber (similar to the contact surface 168 applied in FIG. 14). The thermal guard 166 blocks the flow of heat from the heating region 164 (located partway along the sidewall 126) to the contact surface 168. In some examples, the contact surface 168 may not contact the sidewall 126 to further block conductive heat flow to the contact surface 168, thereby blocking heat flow to the tip 134. The thermal guard 166 may be formed of a material such as plastic, while the contact surface 168 may be formed of a hard wear material such as metal. The contact surface 168 may also distribute pressure evenly across the thermal guard 166.

[0112] The central opening in thermal guard 166 and contact surface 168 may be particularly useful in embodiments utilizing the alternative air flow path shown in the second embodiment.

[0113] Eleventh embodiment Referring to FIG. 16, the heating chamber 108 of the eleventh embodiment is similar to (and operates similarly to) the heating chamber 108 of the first embodiment described with reference to FIGS. 1-6B, except as described below, and the same reference numbers are used to refer to like features.

[0114] The base 112 is formed by a thermal guard 166 that is coupled to the tubular sidewall inside the heating chamber at a distal end and extends across the entire cross section of the heating chamber 108. In an alternative embodiment, the thermal guard 166 may be coupled to the tubular sidewall 126 outside the heating chamber from below the distal end of the tubular sidewall 126. The heating region 164 is located on the tubular sidewall 126 halfway between the two ends 110, 111.

[0115] In this example, the contact surface 168 is simply the top surface of the thermal guard 166, which faces the open first end 110 of the heating chamber. The complete lack of a base reduces thermal mass and increases efficiency. Additionally, assembly of this embodiment is very simple, as it is only necessary to cut the thermal guard 166 to shape and insert it into the open first end 110 of the tubular sidewall.

[0116] Twelfth embodiment Referring to FIG. 17, the heating chamber 108 of the twelfth embodiment is similar to (and operates similarly to) the heating chamber 108 of the first embodiment described with reference to FIGS. 1-6B, except as described below, and the same reference numbers are used to refer to like features.

[0117] In the twelfth embodiment, the base 112 has a recess formed therein within which is provided a thermal guard 166. In the illustrated embodiment, the thermal guard 166 is flush with the base 112.

[0118] In a further embodiment, the thermal guard 166 may form a seat that extends proximally to the base 112, toward the open first end 110 of the heating chamber 108, and is secured in place by a recess.

[0119] In any event, the thermal guard functions to provide a contact surface 168 that faces the open first end 110 of the heating chamber 108. In this manner, the thermal guard 166 blocks a conductive heat flow path from the heating region 164 located partway through the sidewall 126 to the contact surface 168.

[0120] The thermal guard has a contact surface 168 shaped and sized to have an area at least as large as the cross-sectional area of ​​the substrate carrier 114. This means that the tip 134 can fit completely within the contact surface 168. The thermal guard 166 therefore blocks heat flow from the heating region 164 partway along the tubular sidewall 126 to the contact surface 168. In the embodiment of FIG. 17, the thermal guard is flush with the base 112 of the heating chamber 108. In other examples, the thermal guard 166 may extend towards the open first end 110 and thus not be flush with the base 112, but rather form a pedestal. In this latter example, the thermal guard 166 does not need to have a contact surface 168 sized to have an area at least as large as the cross-sectional area of ​​the substrate carrier 114, but instead results in a configuration similar to that shown in the first embodiment.

[0121] Thirteenth embodiment 18A and 18B, the heating chamber 108 according to the thirteenth embodiment is similar to (and operates similarly to) the heating chamber 108 of the first embodiment described with reference to FIGS. 1-6B, except as described below, and the same reference numbers are used to refer to like features.

[0122] 18A and 18B show a heating chamber 10 formed with tubular sidewalls 126a, 166, 126b. The tubular sidewalls are formed in three sections. The proximal first section 126a includes the heating region 164. The middle second section is a thermal guard 166. The distal third section 126b is a further section of the tubular sidewall. In other words, the proximal and distal sections 126a, 126b of the tubular sidewall are joined to each other via the thermal guard 166.

[0123] The third section 126b is joined to a base 112 that includes a pedestal 148, although in other embodiments, the base 112 can be flat. An upper surface of the pedestal 148 faces the open first end 110 of the heating chamber 108 and serves as a contact surface 168.

[0124] The thermal guard 166 blocks the flow of heat from the proximal section of the tubular sidewall 126a to the distal section of the tubular sidewall 126b, which in turn stops the transfer of heat from the heating region 164 to the contact surface 168 on the base 112, which in turn reduces the flow of heat to the tip 134 of the elongated substrate carrier 114.

[0125] It should be noted that this is another example where the roles of thermal guard 166 and contact surface 168 are separated from one another (similar to the situation in the ninth and tenth embodiments). As noted above, this allows the choice of materials for each of thermal guard 166 and contact surface 168 to be selected to optimize the duties they perform.

[0126] The pedestal 148 elevates the tip 134 away from the base and also allows spilled material to fall from the tip 134 without impeding airflow to the tip 134 .

[0127] Fourteenth embodiment 19A, according to a fourteenth embodiment, an insert 192 is provided, which is adapted to be insertable into the heating chamber 108. The insert 192 includes the thermal guard 166, thus allowing an existing heating chamber 108 (which may not include the thermal guard 166) mounted inside the aerosol generating device 100 to be "retrofitted" to include the thermal guard 166. When the insert 192 is inserted into the heating chamber 108, the thermal guard 166 blocks heat flow from the heating region 164 (see FIGS. 19B-19E) of the heating chamber 108 to the contact surface 168 when the insert 192 is inserted into the heating chamber 108. More specifically, the insert 192 is configured to be slid into the heating chamber 108 and also to receive the substrate carrier 114 in the manner described above with respect to the heating chamber 108. The insert 192 may be permanently installed within the heating chamber 108 as part of a one-time retrofit upgrade to an existing heating chamber. Alternatively, the insert 192 may be removable. For example, the insert 192 may be configured to be clipped into place for use with an aerosol generating device, but may be removable once the aerosol substrate 128 has been used. This configuration may aid in removing the substrate carrier 114 after use without damaging the substrate carrier 114, since the substrate carrier 114 may be removed simultaneously with the insert 192 while still being held within the insert 192. Similarly, once the insert 192 is removed, a new substrate carrier 114 may be attached to the insert 192 before both the insert 192 and the substrate carrier 114 are loaded into the heating chamber 108. Loading the insert 192 with the substrate carrier 114 prior to insertion into the heating chamber 108 may allow a user to carefully monitor the loading process, thereby reducing the possibility of damage to the substrate carrier 114, and ensure by visual inspection that the substrate carrier 114 is properly mated with the insert 192. This also allows the insert 192 to be easily cleaned.

[0128] The configuration of the fourteenth embodiment is similar to that described in the previous embodiments, except that the thermal guard is provided in an insert 192 that is inserted into the heating chamber 108. While the insert 192 may be provided in a number of configurations, the illustrated insert 192 is similar in construction to the fourth embodiment of the heating chamber 108 described above in connection with Figure 9. Differences from the previous embodiments are described below. The same reference numbers are used to refer to similar features as the previous embodiments.

[0129] The exemplary insert of FIG. 19A includes a plurality of rod-like elements 176. In the illustrated example, the rods 176 are bent at a second end toward a central axis to form a base. In yet another example, the sidewalls of the insert may be solid and the base may be formed of rods. The base of the insert and the sidewalls of the insert may also be made of mesh or wire netting or any suitable combination as described in connection with the heating chamber 108 shown in FIG. 10. It will be understood that many configurations of the insert 192 similar to the other described embodiments of the heating chamber 108 are possible. In particular, the insert 192 may have solid sidewalls and, optionally, also protrusions 140.

[0130] The base of the insert 192 includes a thermal guard 166 having an upwardly facing contact surface 168. More generally, the thermal guard 166 may be provided at or adjacent the lower end of the insert 192.

[0131] The insert 192 is shown with the optional feature of a rim 107 coupled to the proximal end of the insert 192. The rim 107 is an optional feature, but may have the advantage of allowing the upper end of the insert 192 to rest on or be secured to the upper end of the heating chamber 108 into which the insert 192 is inserted (see, e.g., FIG. 19B). With the insert 192 inserted into the heating chamber, all or part of the rim 107 may be located outside the interior of the heating chamber 108 for easy access or gripping by a user, thereby allowing removal of the insert 192 (e.g., for cleaning). The rim 107 of the insert 192 may also provide additional structural support to the side walls of the insert 192. In the illustrated example, the upper end of the rod 176 is secured within the rim 107, thereby helping to protect the rod 176 from damage, e.g., due to bending.

[0132] 19B and 19C, the insert 192 is configured to have dimensions such that it can be inserted into the heat chamber, and when inserted into the heat chamber, the thermal guard 166 blocks heat transfer from the heating region 164 of the heat chamber to the contact surface 168 of the thermal guard 166. In FIG. 19B, the insert 192 is shown inserted into the heat chamber 108. In the illustrated example, the rod 176 of the insert 192 is configured to be positioned flush with the sidewall 126 of the heat chamber. This allows heat to be transferred from the sidewall 126 of the heat chamber 108 to the insert 192 by conduction. The illustrated insert 192 is also configured such that the underside of the thermal guard 166 contacts the base of the heat chamber 108 when the insert 192 is inserted into the heat chamber, as shown in FIG. 19C.

[0133] It will be appreciated that with the rod 176 contacting the sidewall 126 of the heating chamber 108 at the heating region 164, the thermal guard 166 will block heat transfer from the heating region 164 to the contact surface 168, which in turn blocks heat transfer from the heating region 164 to the tip 134 of the substrate carrier 114. It will also be appreciated that if the underside of the insert's thermal guard 166 were to contact the base of the heating chamber 108 (where heat could be transferred from the heating region 164 through the sidewall 126 of the heating chamber 108), the thermal guard 166 would block heat transfer from the heating region 164 to the contact surface 168.

[0134] Additionally, the insert 192 is configured to receive an elongated substrate carrier 114 in a manner similar to the previous embodiment, as shown in FIG. 19C. The insert 192 shown is dimensioned such that the rods 176 press against the substrate carrier when the substrate carrier is inserted into the insert. This may provide an interference fit between the substrate carrier 114 and the insert 192 and improved heat transfer from the rods 176 of the insert 192 to the aerosol substrate 128. With the substrate carrier 114 inserted into the insert 192, the tip 134 of the substrate carrier 114 contacts the contact surface 168. There is an annular portion of the tip 134 of the substrate carrier 114 that is not in contact with the contact surface 168. By comparing FIG. 19A and FIG. 19C, it can be seen that there is an air flow path that allows air to be drawn from outside the heating chamber 108 through the gaps between the rods 176 of the insert 192 to the tip 134 of the substrate carrier 114. In an alternative embodiment, the sidewalls of the insert 192 may be solid and in such a configuration an air flow passage according to the second embodiment may be appropriate. In another example, a spacer 190 may be used, as described below with reference to FIG. 19E.

[0135] 19D shows an aerosol generating device 100 including a heating chamber 108 having an insert 192 with a thermal guard 166 according to the fourteenth embodiment. The rim 107 of the insert 192 rests on the open first end 110 of the heating chamber 108 and the rod 176 forming the sidewall of the insert 192 is disposed flush along the sidewall 126 of the heating chamber. The substrate carrier 114 is inserted into the insert 192 for use and contacts the contact surface 168 at its tip 134.

[0136] In Fig. 19E, an alternative insert 192 to those shown in Figs. 19A-19D is shown inserted into the heating chamber 108 in the aerosol generating device 100. In this example, the insert 192 has a solid sidewall (i.e., not formed of a rod 176 as in Figs. 19A-19D) and is dimensioned such that the substrate carrier 114 is not compressed by the sidewall of the insert 192 when inserted into the insert 192. In fact, a gap is maintained between the sidewall of the insert 192 and the substrate carrier 114 by a spacer 190 in a manner similar to that shown in Fig. 8C. The spacer 190 is provided above the open first end 110 of the heating chamber 108 and is configured to hold the substrate carrier 114 within the insert 192 such that a gap is maintained between the outer layer 132 of the substrate carrier 114 and the sidewall of the insert 192. The spacer 190 may be removable as described above (FIG. 8C) to allow for insertion / removal of the insert 192 into the heating chamber. In some examples, the spacer 190 may be attached to the insert 192 to aid in this.

[0137] For example, other configurations of the insert 192 are possible where the base of the insert 192 or the thermal guard 166 does not contact the base of the heat chamber 108 when the insert 192 is inserted into the heat chamber, or where the sidewalls (or bars 176) of the insert 192 are not positioned flush with the heat chamber 108. In this latter example, the spacers 190 may be used to ensure that the insert 192 (and the substrate carrier 114 held within the insert 192) are maintained in their intended position, centered within the heat chamber 108.

[0138] Definitions and Alternative Embodiments From the above description, it will be understood that many features of the various embodiments are interchangeable. The disclosure extends to further embodiments including those in which features of the various embodiments are combined together in a manner not specifically mentioned. For example, in each case, any of the thermal guard configurations shown herein may be used with any of the air flow paths (first and second embodiments) with minor modifications to the base to allow air to flow through the base to the heating chamber 108. Similarly, the bars or mesh walls of the fourth and fifth embodiments may be applied to any of the different embodiments of the thermal guard 166. The protrusions 140 for compressing the aerosol substrate provided in the first embodiment may be provided in any of the other embodiments, with their associated advantages. Similarly, the insert may comprise any of the features of the heating chamber embodiments disclosed herein and may be dimensioned to accommodate any suitable heating chamber.

[0139] Each heating chamber 108 may include a flange or rim at the open first end 110 for structural support and may optionally be formed of a thermally insulating material to prevent heat dissipation into the outer casing 102.

[0140] 6A, 6B and 8-18 show the heating chamber 108 separated from the aerosol generating device 100. This emphasizes that the advantageous features described with respect to the design of the heating chamber 108 are independent of other features of the aerosol generating device 100. In particular, there are many applications of the heating chamber 108, not all of which are relevant to the aerosol generating device 100 described herein. Such designs may benefit from protrusions to conduct heat to the aerosol substrate and / or compress the aerosol substrate and / or provide strength to the side walls 126 of such heating chambers. For such applications, the heating chambers described herein are advantageously provided.

[0141] Furthermore, the heating chamber 108 shown in any embodiment may be removable from the aerosol generating device 100, for example, for cleaning. In such cases, the heating region 164 is typically not used to mount the heater 124, since making electrical connections to the heater may introduce complications into a removable heating chamber 108. Instead, the heating chamber may have a heating region 164 configured to be heated, for example, inductively, radiatively, or by combustion. If the heating chamber is removable, a thermal guard may be placed outside the heating chamber, for example, between the wall of the cavity into which the heating chamber 108 fits and the heating chamber itself.

[0142] It will be appreciated that in some embodiments, it may be preferred that the thermal guard 166 and / or contact surface 168 be used in conjunction with another air flow path as described in the second embodiment to allow air to flow to the tip 134 of the substrate carrier 114. In other examples, the contact surface 168 may not be flat (as shown diagrammatically in the figures) but may be convex or shaped to extend inwardly into the heating chamber 108 to provide a seat for contacting the tip 134, which may further allow air to flow to the tip 134.

[0143] The term "heater" should be understood to mean any device for outputting sufficient thermal energy from the aerosol substrate 128 to form an aerosol. The transfer of thermal energy from the heater 124 to the aerosol substrate 128 can be by conduction, convection, radiation, or any combination of these means. As a non-limiting example, a conductive heater may directly contact and press against the aerosol substrate 128, or may contact a separate component that itself causes heating of the aerosol substrate 128 by conduction, convection, and / or radiation. Convection heating may include heating a liquid or gas, which results in thermal energy being transferred (directly or indirectly) to the aerosol substrate.

[0144] Radiative heating includes, but is not limited to, transferring energy to the aerosol 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 substrate 128 resulting in heating, or the radiation may be absorbed by another material, such as a susceptor or fluorescent material, such that the radiation is re-emitted at a different wavelength or spectral weighting. In some cases, the radiation may be absorbed by a material which then transfers heat to the aerosol substrate 128 by any combination of conduction, convection and / or radiation.

[0145] The heater may be electrically powered, combustion powered, or powered by any other suitable means. Electrically powered heaters may include resistive track elements (optionally including insulating packaging), inductive heating systems (including, for example, electromagnets and high frequency oscillators), etc. The heater may be positioned around the outside of the aerosol substrate 128, may penetrate partway or completely within the aerosol substrate 128, or any combination thereof.

[0146] The term "temperature sensor" is used to describe an element capable of determining the absolute or relative temperature of a portion of the aerosol generating device 100. This may include a thermocouple, a thermopile, a thermistor, etc. The temperature sensor may be provided as part of another component or may be a separate component. In some examples, multiple temperature sensors may be provided, for example to monitor the heating of various portions of the aerosol generating device 100, for example to determine a thermal profile.

[0147] With reference to the above-mentioned embodiments, the aerosol substrate 128 includes tobacco, for example in a dried or cured form, optionally with additional ingredients for flavor or to provide a smoother or more satisfying effect. In some examples, the aerosol substrate 128, such as tobacco, may be treated with a vaporizer. The vaporizer may improve the generation of aerosol from the aerosol substrate. The vaporizer may include, for example, a polyol, such as glycerol, or a glycol, such as propylene glycol. In some cases, the aerosol substrate may not include tobacco or even nicotine, but instead may include natural or artificial ingredients for flavoring, volatility, improved smoothness, and / or other satisfying effects. The aerosol substrate 128 may be provided as a solid or paste-type material in shredded, pelleted, powdered, granular, strip or sheet form, optionally a combination thereof. Similarly, the aerosol substrate 128 may be liquid or gel. Indeed, in some examples, both solid and liquid / gel portions may be included.

[0148] Thus, the aerosol generating device 100 may equally be referred to as a "heated tobacco device," a "heated non-combustion tobacco device," a "device for vaporizing tobacco products," etc., and is to be construed as a device suitable for achieving these effects. The features disclosed herein are equally applicable to devices designed to vaporize any aerosol substrate.

[0149] An embodiment of the aerosol generating device 100 is described as being configured to house the aerosol substrate 128 within a prepackaged substrate carrier 114. The substrate carrier 114 may generally resemble a cigarette with a tubular region having the aerosol substrate arranged in an appropriate manner. Some designs may also include filters, aerosol collection regions, cooling regions, and other structures. For example, a flexible flat material such as an outer layer of paper or other foil to hold the aerosol substrate in place may also be provided to further enhance the resemblance to a cigarette or the like.

[0150] As used herein, the term "fluid" shall be taken to collectively describe a type of non-solid material that is capable of flowing, including, but not limited to, liquids, pastes, gels, powders, etc. Accordingly, a "fluidized material" shall be taken as a material that is inherently fluid or that has been modified to behave as a fluid. Fluidization may include, but is not limited to, powdering, dissolving in a solvent, gelling, thickening, thinning, etc.

[0151] As used herein, the term "volatile" refers to a material that can be easily changed from a solid or liquid state to a gaseous state. As a non-limiting example, a volatile material may have a boiling or sublimation temperature near room temperature at ambient pressure. Thus, "volatilize" or "volatilise" shall be interpreted to mean to cause (a material) to volatilize and / or to evaporate or disperse into a vapor.

[0152] As used herein, the term "vapour" (or "vapor") means: (i) the form into which a liquid is transformed spontaneously by the action of a sufficient degree of heat, or (ii) liquid / moisture particles suspended in the atmosphere and visible as a cloud of steam / smoke, or (iii) a fluid that fills space like a gas but can be liquefied by pressure alone when below a critical temperature.

[0153] Consistent with this definition, the term "vaporise" (or "vaporize") means: (i) to change or cause to change into a vapor, and (ii) when a particle changes physical state (i.e., from a liquid or solid to a gaseous state).

[0154] As used herein, the term "atomise" (or "atomize") shall mean: (i) to change (a substance, especially a liquid) into very small particles or droplets, and (ii) where the particles remain in the same physical state (liquid or solid) as they were before atomization.

[0155] As used herein, the term "aerosol" shall mean a system of particles dispersed in air or gas, such as mist, fog, or smoke. Thus, the term "aerosolize" (or "aerosolize") means to make into an aerosol and / or to disperse as an aerosol. It is noted that the meaning of aerosol / aerosolize is consistent with each of volatilization, atomization, and vaporization defined above. For the avoidance of doubt, aerosol is used consistently to describe mist or droplets containing atomized, volatilized, or vaporized particles. Aerosol also includes mist or droplets containing any combination of atomized, volatilized, or vaporized particles.

Claims

1. 1. A heating chamber (108) for an aerosol generating device (100), the aerosol generating device (100) having a heater (124) disposed externally of the heating chamber (108), the heating chamber (108) for receiving an elongated substrate carrier (114) having an aerosol substrate (128) disposed toward an end (134) of the elongated substrate carrier (114), and the heating chamber (108) comprising: a tubular sidewall (126) defining an interior volume and having an open first end (110) and a second end (111) distal to said first end (110), said elongated substrate carrier (114) being receivable within said interior volume through said open first end (110), said second end being closed by a base (112), and wherein air drawn into said heating chamber from said open first end (110) flows through a gap between said tubular sidewall (126) and said elongated substrate carrier (114) to said end (134) of said elongated substrate carrier (114); a heating region (164) through which heat from the externally disposed heater (124) is applied to the heating chamber (108); a contact surface (168) exposed to the interior volume for contacting the substrate support (114) at or near the second end (111); a thermal guard (166) for blocking heat flow from the heating area (164) to at least one of the contact surfaces (168) in the base (112); a heating chamber (108) including

2. A heating chamber (108) as described in claim 1, wherein at least one of the contact surfaces (168) faces the first end (110) of the tubular side wall (126).

3. 3. The heating chamber of claim 1, wherein the thermal guard comprises a first material and the tubular sidewall comprises a second material, the first material having a lower thermal conductivity than the second material.

4. The heating chamber (108) of claim 3, wherein the thermal guard is made of ceramic and / or the tubular side wall is made of metal.

5. A heating chamber (108) as described in any one of claims 1 to 4, wherein at least one of the contact surfaces (168) is a surface of the thermal guard (166).

6. The heating chamber (108) of any one of claims 1 to 5, wherein the thermal guard (166) is annular.

7. The heating chamber (108) of any one of claims 1 to 6, wherein the heating region (164) comprises a portion of the tubular side wall (108).

8. The heating chamber (108) of any one of claims 1 to 7, wherein the thermal guard (166) extends inwardly from the base (112) towards the interior volume to provide a seat for supporting the substrate support (114).

9. The heating chamber (108) of any one of claims 1 to 8, wherein the thermal guard (166) extends across the entire width of the base (112).

10. The heating chamber (108) of any one of claims 1 to 9, wherein the thermal guard (166) is a separate element attached to the base (112).

11. The heating chamber (108) of any one of claims 1 to 10, further comprising an insert (192) including the thermal guard (166), the insert (192) being positioned for removable insertion into the interior volume of the heating chamber (108).

12. The heating chamber (108) of claim 11, wherein the insert comprises a mesh or wire netting or a plurality of bar-shaped elements.

13. An aerosol generating device (100) comprising a heating chamber (108) according to any one of claims 1 to 12 and the heater (124), wherein the heater (124) is attached to the tubular side wall (126) and the heating region (164) is defined by an area of ​​the tubular side wall (126) that is at least partially overlapped by the heater (124).

14. 14. The aerosol generating device (100) of claim 13, wherein the heater (124) is attached to a surface of the tubular sidewall (126) facing away from the interior volume.

15. A power source (120); a control circuit (122) configured to control the supply of power from the power source to the heater (124); 15. The aerosol generating device (100) according to claim 13 or 14, comprising:

16. The aerosol generating device (100) of any one of claims 13 to 15, further comprising a spacer (190) for holding the substrate support (114) in a central configuration within the heating chamber (108).

17. The aerosol generating device (100) of claim 16, wherein the spacer (190) is removably coupled to the aerosol generating device (100).

18. An aerosol generation system comprising an aerosol generation device (100) according to any one of claims 13 to 17 and said substrate carrier (114).

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