Heating chamber for aerosol generating device

Abstract

A heating chamber (11) for an aerosol generating device (1), the heating chamber (11) including a compression element (111) containing a thermally active material and a reaction surface (112), the heating chamber (11) adapted to accommodate an aerosol substrate (2) between the compression element (111) and the reaction surface (112), the compression element (111) configured to compress the aerosol substrate against the reaction surface (112), and the compression element (111) configured to displace in response to the temperature of the heating chamber (11) and a thermal response characteristic of the magnetic properties of the thermally active material.

Description

[Technical Field]

[0001] The present disclosure relates to aerosol generating devices. The present disclosure is particularly applicable to self-contained, low-temperature, portable aerosol generating devices that can generate an aerosol for inhalation by heating tobacco or other suitable aerosol substrate by conduction, convection, and / or radiation, rather than by combustion. [Background technology]

[0002] The popularity and use of risk reduction or risk modification devices (also known as vapor generators) has grown rapidly over the past few years as aids to assist habitual smokers who wish to quit using traditional tobacco products, such as cigarettes, cigars, cigarillos, cigarettes, etc. A variety of devices and systems are available that heat or warm an aerosolizable substance, as opposed to burning tobacco as in traditional tobacco products.

[0003] A commonly available risk-reducing or risk-modifying device is the heated substrate aerosol generator, or heat-not-burn (HNB) device. This type of device generates an aerosol or vapor by heating an aerosol substrate (i.e., a consumable) containing moist tobacco or other suitable aerosolizable material, typically to temperatures between 150°C and 300°C. Heating the aerosol substrate without burning it releases an aerosol containing the ingredients desired by the user, but without releasing the toxic and carcinogenic by-products of combustion. Additionally, the aerosol generated by heating tobacco or other aerosolizable material typically does not contain the burnt or bitter taste that can be unpleasant to users as a result of combustion.

[0004] However, in such devices, the aerosol substrate is known to lose structural integrity during the heating process and may begin to shrink and / or release aerosol material, which can result in uneven heating of the aerosol substrate and adversely affect the aerosol generating properties of the device.

[0005] Furthermore, if the user removes the aerosol base from the device during heating operation, there is a risk that the user may come into contact with a hot part of the aerosol base.

[0006] It is therefore an object of the present invention to solve one or more of these problems. Summary of the Invention

[0007] According to a first aspect, the present disclosure provides a heating chamber for an aerosol generating device, the heating chamber including a compression element including a thermally active material and a reaction surface, the heating chamber adapted to accommodate an aerosol substrate between the compression element and the reaction surface, the compression element configured to compress the aerosol substrate against the reaction surface, and the compression element configured to displace in response to a temperature of the heating chamber and a thermal response characteristic of a magnetic property of the thermally active material.

[0008] Compressing the aerosol substrate in response to the temperature of the heating chamber allows for stable heating and prevents the aerosol substrate from being removed at a high temperature. Compressing the aerosol substrate while heating it also improves aerosol production. Furthermore, the thermal response of the magnetic properties is a passive response, and no control circuit is required to control the displacement.

[0009] Optionally, the heating chamber further comprises a heating element disposed on, behind, or built into the compression element. Optionally, the heating chamber further comprises a heating element disposed on, behind, or built into the reaction surface. By providing a heating element on, behind, or within the compression element and / or reaction surface, the heating element remains in proximity to the aerosol substrate despite any displacement and compression, further improving heating uniformity.

[0010] Optionally, the reaction surface is a second compression element configured to displace in response to the temperature of the heating chamber. Compression by two opposing elements can improve compression uniformity across the aerosol matrix. Additionally, the range of motion of each compression element can be halved compared to the single compression element example. The reduced range of motion allows for the use of thermally activated materials with reduced maximum magnetic field strengths or reduced amounts of thermally activated materials.

[0011] Optionally, the heating chamber further includes a magnetic interacting element including a first magnetic material, the thermally active material including a second magnetic material, the compression element displaced in response to a change in magnetic force between the first and second magnetic materials, at least one of the first and second magnetic materials having a threshold temperature at which the material undergoes a magnetic phase transition, and the heating chamber configured to raise the temperature of the heating chamber to an aerosol-generating temperature above the threshold temperature during aerosol generation. By providing a magnetic interacting element configured to interact with the thermally active material and designing the thermally active material to undergo a magnetic phase transition, the compression element can be configured to move smoothly between an open position in which the aerosol substrate can be removed from the heating chamber and a closed position in which a compressive force is applied to retain the aerosol substrate.

[0012] Optionally, a compression element is disposed between the magnetic interaction element and the reaction surface, one of the first and second magnetic materials being ferromagnetic up to a Curie temperature below the aerosol-generation temperature, and the other of the first and second magnetic materials being paramagnetic above the Curie temperature, In this configuration, magnetic forces hold the compression element open in the cold state (below the Curie temperature), and the compression element does not inhibit the addition or removal of aerosol substrate in the cold state.

[0013] Optionally, a magnetic interactive element is disposed on or behind the reaction surface, or is contained within, wherein one of the first and second magnetic materials is antiferromagnetic up to a Neel temperature below the aerosol-generating temperature, and the other of the first and second magnetic materials is ferromagnetic at the aerosol-generating temperature. In this configuration, magnetic forces hold the compression element closed at high temperatures (above the Neel temperature).

[0014] Optionally, a magnetic interactive element is disposed on or behind the reaction surface, or is contained within, wherein one of the first and second magnetic materials is ferromagnetic up to a Curie temperature below the aerosol-generation temperature, and the other of the first and second magnetic materials is diamagnetic, In this configuration, at low temperatures (below the Curie temperature), the magnetic force holds the compression element open.

[0015] Optionally, the heating chamber further comprises a resilient element configured to bias the compression element toward or away from the reaction surface, the resilient element may be configured to counteract a force applied due to the magnetic properties of the thermally active material to bias the compression element in two different directions depending on the temperature within the heating chamber.

[0016] According to a second aspect, the present disclosure provides an aerosol generating device comprising a heating chamber as described above.

[0017] According to a third aspect, the present disclosure provides an aerosol generating system comprising a heating chamber as described above and an aerosol substrate disposed between the compression element and the reaction surface.

[0018] According to a fourth aspect, the present disclosure provides a method of generating an aerosol, the method comprising the steps of providing an aerosol substrate between a compression element and a reaction surface of a heating chamber as described above; operating the heating chamber to raise the temperature of the heating chamber to an aerosol-generating temperature; extracting an aerosol from the heating chamber; operating the heating chamber to lower the temperature of the heating chamber to an aerosol substrate release temperature; and removing the aerosol substrate from the heating chamber. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a schematic cross-sectional view of an aerosol generating device containing consumables. [Figure 2A] 1 is a schematic cross-sectional view of a heating chamber according to a first embodiment, including an aerosol substrate; FIG. [Figure 2B] 1 is a schematic cross-sectional view of a heating chamber according to a first embodiment, including an aerosol substrate; FIG. [Figure 3] FIG. 2 is a schematic cross-sectional view of a heating chamber according to a second embodiment, including an aerosol substrate. [Figure 4] FIG. 10 is a schematic cross-sectional view of a heating chamber according to a third embodiment, including an aerosol substrate. [Figure 5] FIG. 1 is a schematic cross-sectional view of an alternative aerosol generating device containing consumables. [Figure 6] FIG. 2 is a schematic cross-sectional view of a heating chamber including an air flow path. DETAILED DESCRIPTION OF THE INVENTION

[0020] FIG. 1 is a schematic cross-sectional view of an aerosol generating device incorporating a heating chamber according to the present disclosure.

[0021] The aerosol generating device 1 includes a heating chamber 11, a power supply 12, and a control circuit 13. The control circuit 13 controls the supply of power from the power supply 12 to the heating chamber 11 so as to heat the consumables 2 contained in the heating chamber 11.

[0022] The heating chamber 11 includes a compression element 111 and a reaction surface 112. The consumable 2 is housed between the compression element 111 and the reaction surface 112, and the compression element 111 is configured to be displaced to compress the consumable 2 against the reaction surface 112.

[0023] Specifically, the consumable product includes at least an aerosol substrate 21 disposed in a heating chamber 11 to generate an aerosol. The consumable product may take the form of, for example, a cigarette in which the aerosol substrate is contained in a wrapper. The cigarette may additionally include a mouthpiece 22 that includes a filter. In this configuration, the aerosol substrate 21 is heated to generate an aerosol, which can be inhaled by a user through the mouthpiece 22.

[0024] To facilitate inhalation of the aerosol, the aerosol generating device may include an air flow passage having an inlet and an outlet at different points in the housing of the aerosol generating device, the air flow passage extending through the heating chamber 11.

[0025] In particular, the aerosol generating device may include an opening capable of receiving the consumable 2 and configured as an outlet for the air flow path. In embodiments in which the consumable 2 does not include a mouthpiece 22, the aerosol generating device may include a mouthpiece combined with or separate from the opening through which the consumable 2 is inserted into the heating chamber 11. For example, the opening through which the consumable 2 is inserted may have a lid that includes a mouthpiece.

[0026] Power supply 12 may be, for example, a battery or a connection to an external power source.

[0027] The control circuit 13 may include a general purpose programmable circuit or hardwired logic circuit that controls the heating chamber 11 .

[0028] The control circuit 13 may also include a temperature sensor that determines the temperature of the heat chamber 11. Alternatively, the control circuit 13 may estimate the temperature of the heat chamber 11 based on how the heat chamber 11 has been recently controlled.

[0029] The control circuit 13 may also include a user interface such as a button or slider for activating aerosol generation within the heating chamber, or for controlling the characteristics of the aerosol generation, such as the length of time of the aerosol generation operation, or the temperature profile of how quickly the consumable 2 heats up, or the peak temperature to which the consumable 2 is heated.

[0030] In use, the aerosol generating device 1 may operate as follows. Providing the consumable 2 in the heating chamber 11 between the compression element 111 and the reaction surface 112. This may be performed by a user of the aerosol generating device. Operating the heating chamber 11 to raise the temperature of the heating chamber 11 to an aerosol-generating temperature that is at least high enough to release an aerosol from the aerosol substrate 21 of the consumable 2. Heat may be supplied to one or more heating elements 115 included in the heating chamber 11. Extracting the aerosol from the heating chamber 11, for example so that the user can inhale it through the mouthpiece 22. Operating the heating chamber 11 to reduce the temperature of the heating chamber 11 to the aerosol substrate release temperature. This can be achieved passively by turning off the heat supply to the heating chamber 11. Removing the consumable 2 from the heating chamber 11. This may be done by the user after the consumable 2 has been released.

[0031] In embodiments of the present invention, the compression element 111 comprises a thermally active material configured such that at least a portion of the displacement of the compression element 111 occurs passively in response to the temperature of the heating chamber 11 and the thermal response characteristics of the thermally active material. In some embodiments, this passive displacement may be combined with actively controlled displacement, such as actuator-driven displacement, but this is not required.

[0032] In particular, the compression element 111 comprises a material whose magnetic properties change depending on the temperature of the material. For example, as shown with reference to certain embodiments, this change in magnetic properties can be a phase transition between two types of magnetic behavior, including ferromagnetic, paramagnetic, antiferromagnetic, and diamagnetic behavior. As used herein, "ferromagnetic" includes both ferromagnetic and ferromagnetic behavior. Alternatively (though less preferred), the change in magnetic properties can be a continuous change in magnetic field strength without a phase transition. A phase transition is preferred because the transition can generate relatively high instantaneous forces so that displacement of the compression element can overcome friction or any stickiness associated with, for example, aerosol generation by-products.

[0033] 2A and 2B are schematic cross-sectional views of the heating chamber 11 showing additional details of the compression element 111 and reaction surface 112 in the first embodiment, the cross-section extending in a plane along the "length" of the consumable 2 as shown in FIG.

[0034] In a first embodiment, the compression element 111 magnetically interacts with the magnetic interaction element 113. The magnetic interaction element 113 may be, for example, one or more pieces of a first magnetic material mounted inside the heating chamber 11 such that the compression element 111 is disposed between the magnetic interaction element 113 and the reaction surface 112.

[0035] In this configuration, the thermally active material of the compression element 111 includes a second magnetic material that may be the same as or different from the first magnetic material of the magnetic interaction element 113. During an aerosol generation operation, the temperature of the heating chamber 11 is raised to an aerosol-generation temperature at which an aerosol is generated from the consumable 2. As the temperature of the heating chamber 11 increases during an aerosol generation operation, the magnetic properties of at least one of the first and second magnetic materials change, thereby changing the force of interaction between the compression element 111 and the magnetic interaction element 113.

[0036] In a particular configuration of the first embodiment, when the heating chamber 11 is in the cold state shown in Figure 2A, at least one of the first and second magnetic materials is ferromagnetic, while the other of the first and second magnetic materials may be ferromagnetic or paramagnetic. As a result, the compression element 111 and the magnetic interaction element 113 are subjected to an attractive force that biases the compression element 111 away from the reaction surface 112.

[0037] 2A, when the heating chamber 11 is the aerosol generation chamber and in a high temperature state, both the first and second magnetic materials are paramagnetic, and there is no significant attraction between the compressed body 111 and the magnetic interaction element 113. To achieve this, if the magnetic material has a paramagnetic temperature range, it must be selected so that the upper limit of that range (Curie temperature) is lower than the aerosol generation temperature.

[0038] Once the heating chamber 11 cools below the Curie temperature (aerosol substrate release temperature), the magnetic properties return to a low temperature state and the compression element 111 and magnetic interaction element 113 are again subjected to an attractive force, returning the compression element 111 to an open position where the consumable 2 can be inserted and removed.

[0039] 2A and 2B, a second force is applied to displace the compression element 111 when the magnetic interaction is extinguished at temperatures above the Curie temperature. For example, a resilient element 114 (such as a spring) can be positioned adjacent to the magnetic interaction element 113 to provide a force that counteracts the attractive force between the magnetic interaction element 113 and the compression element 111, biasing the compression element 111 away from the reaction surface 112. When the magnetic attraction is extinguished, the resilient element 114 displaces the compression element 111 toward the reaction surface 112, causing compression of the aerosol substrate 21.

[0040] 2A and 2B, one or more heating elements 115 may be provided to provide heat within the chamber 11. The heating elements 115 may be any known type of heating element, such as a combustible heating element or an electronic resistance heating element.

[0041] The heating element 115 may be located at various positions around the heating chamber 11. For example, the heating element 115 may be located on (on or contained within) the compression element 111. In this case, since the compression element 111 is configured to be displaceable, it may be necessary to provide the heating element 115 with a flexible or sliding fuel / power supply. However, since the compression element 111 is configured to compress the aerosol substrate 21, this arrangement provides the advantage of improved thermal contact and more efficient heating of the substrate.

[0042] Alternatively or additionally, the heating element 115 may be located in a fixed position such as in the wall of the heating chamber, for example behind the compression element 111 (i.e., the compression element is between the heating element and the reaction surface), or on the reaction surface 112 (located on or embedded within the reaction surface 112).

[0043] FIG. 3 shows a second embodiment of the heating chamber 11 as a variation of the first embodiment shown in FIGS. 2A and 2B. The second embodiment differs from the first embodiment in that the reaction surface is not a fixed surface, but is configured to displace in a manner similar to that described above for the compression element. In other words, the reaction surface 112 may be configured as a second compression element configured to displace in response to the temperature of the heating chamber. In a simple case, the heating chamber 11 is substantially symmetrical in displacement to the second compression element 112, which is configured to function similarly to the first compression element 111.

[0044] More generally, the number of compression elements is not limited. For example, the chamber 11 may have a triangular configuration arranged to receive the consumable 2 between three compression elements spaced 120 degrees apart around the circumference of the consumable 2. In this case, the "reaction surface" function of each compression element is divided between the other two compression elements.

[0045] FIG. 4 shows an alternative arrangement in a third embodiment, which is a modification of the first embodiment.

[0046] In a third embodiment, the magnetic interaction element 113 is positioned opposite the compression element 111 across the heating chamber 11 so as to receive the consumable 2 between the magnetic interaction element 113 and the compression element 111. In this case, the magnetic interaction element 113 may be positioned adjacent to the reaction surface 112 or in combination with the reaction surface 112 (e.g., positioned on, within, or behind the reaction surface).

[0047] In the third embodiment, multiple types of magnetic configurations can be used.

[0048] In a first case, the compression element 111 and the magnetic interaction element 113 may be configured to experience no magnetic attraction at low temperatures but experience magnetic attraction at the aerosol-generation temperature. This can be achieved by using a magnetic material for one of the compression element 111 and the magnetic interaction element 113 that is antiferromagnetic at temperatures below the Neel temperature, which is lower than the aerosol-generation temperature, and a magnetic material for the other of the compression element 111 and the magnetic interaction element 113 that is ferromagnetic at the aerosol-generation temperature.

[0049] At the same time, in the first case, the elastic element 114 may be configured to bias the compression element 111 towards an open position from which the consumable 2 is released. In this way, when the heating chamber 11 is cold (e.g., close to room temperature), the consumable 2 can be inserted and removed. Alternatively, since there is no magnetic force at cold temperatures in this configuration, the elastic element 114 may be omitted, leaving it to the user of the aerosol generation device to exert minimal force to move the compression element 111 to an open position from which the consumable 2 can be inserted and removed.

[0050] In a second case, the compression element 111 and the magnetic interaction element 113 may be configured to experience a repulsive magnetic force at low temperatures, but not at aerosol-generating temperatures.

[0051] This can be achieved by arranging two ferromagnetic materials facing each other in a repulsive configuration. More specifically, the compression element 111 can be arranged so that its magnetic field points in a first direction, and the magnetic interaction element 113 can be arranged so that its magnetic field points in a direction opposite to the first direction. Provided that at least one of the first magnetic material used in the magnetic interaction element 113 and the second magnetic material used in the compression element 111 has a Curie temperature lower than the aerosol-generation temperature, the repulsive magnetic force is not present when the heating chamber 11 is at the aerosol-generation temperature.

[0052] Alternatively, and more preferably, the second case can be achieved by using ferromagnetic and ferrodiamagnetic materials so that alignment of the magnetic fields is not required. More specifically, the diamagnetic material generates a magnetic field that opposes the magnetic field of the ferromagnetic material, and the ferromagnetic and diamagnetic materials repel each other. If the Curie temperature of the ferromagnetic material is lower than the aerosol-generation temperature, no repulsion occurs at the aerosol-generation temperature.

[0053] In the second case, the elastic element 114 may be configured to bias the compression element 111 towards the reaction surface 112, similar to the first embodiment.

[0054] Figure 5 is a schematic cross-sectional view of an alternative aerosol generation device 1 containing a consumable item 2. The aerosol generation device 1 and the consumable item 2 have substantially similar features to those described with reference to Figure 1, and only the differences will be described here.

[0055] In Figure 1, the air flow path extends through the aerosol generation device 1 between an inlet and a separate outlet. However, as shown in Figure 5, the inlet and outlet of the air flow path may alternatively be at the same point on the housing of the aerosol generation device, and the heating chamber 11 may have a pan-like configuration with only one opening. In this configuration, air is drawn into the aerosol substrate 21 through one part of the opening and expelled out of the aerosol substrate 21 through another part of the opening.

[0056] Such differences in air flow paths may require modifications to the heating chamber 11 as shown in FIG.

[0057] More specifically, as shown in FIG. 6 , the heating chamber 11 may include one or more protrusions 116 configured to maintain a space between the consumable 2 and the walls of the heating chamber 11 to allow air to flow around the consumable 2. These protrusions may be, for example, ribs extending along the heating chamber 11. The protrusions 116 should be configured so as not to impede the displacement of the compression element 111. Nevertheless, the protrusions 116 may provide a synergistic benefit of aiding compression by limiting the cross-section of the heating chamber 11 that the consumable 2 can occupy.

[0058] In one embodiment, the compression element 111 itself may be configured to maintain an air flow path around the consumable 2, similar to the protrusions 116. That is, the compression element 111 may be disposed between the inlet portion of the heating chamber 11 and the consumable storage portion of the heating chamber 11. Therefore, when the compression element 111 is displaced to compress the consumable 2, it has the secondary effect of widening the cross-section of the flow path through which air flows into the heating chamber 11. In such an embodiment, a pot-shaped heating chamber 11 may be used without providing the protrusions 116 separately from the compression element 111.

Claims

1. 1. A heating chamber for an aerosol generating device, comprising: a compression element including a thermally active material; a reactive surface; the heating chamber is adapted to contain an aerosol substrate between the compression element and the reaction surface, the compression element being configured to compress the aerosol substrate against the reaction surface; the compression element is configured to be displaced in response to a temperature of the heating chamber and a thermal response characteristic of a magnetic property of the thermally active material; the heating chamber further includes a magnetically interactive element including a first magnetic material; the thermally active material includes a second magnetic material; the compression element displaces in response to a change in magnetic force between the first and second magnetic materials; at least one of the first and second magnetic materials has a threshold temperature at which the material undergoes a magnetic phase transition; The heating chamber is configured to increase the temperature of the heating chamber during aerosol generation to an aerosol-generating temperature that exceeds the threshold temperature.

2. The heating chamber of claim 1 further comprising a heating element disposed on the compression element.

3. The heating chamber of claim 1 or 2, further comprising a heating element disposed on the reaction surface.

4. 4. The heating chamber of claim 1, wherein the reaction surface is a second compression element configured to be displaced in response to the temperature of the heating chamber.

5. the compression element is disposed between the magnetic interaction element and the reaction surface; 2. The heating chamber of claim 1, wherein one of the first and second magnetic materials is ferromagnetic up to a Curie temperature lower than the aerosol generation temperature, and the other of the first and second magnetic materials is paramagnetic above the Curie temperature.

6. the magnetic interactive element is disposed on the reaction surface; 2. The heating chamber of claim 1, wherein one of the first and second magnetic materials is antiferromagnetic up to a Neel temperature lower than the aerosol-generating temperature, and the other of the first and second magnetic materials is ferromagnetic at the aerosol-generating temperature.

7. the magnetic interactive element is disposed on the reaction surface; 2. The heating chamber of claim 1, wherein one of the first and second magnetic materials is ferromagnetic up to a Curie temperature below the aerosol-generating temperature, and the other of the first and second magnetic materials is diamagnetic.

8. The heating chamber of claim 1 , further comprising a resilient element configured to bias the compression element towards or away from the reaction surface.

9. 9. An aerosol generating device comprising a heating chamber according to any one of claims 1 to 8.

10. 9. An aerosol generating system comprising the heating chamber of claim 1 and an aerosol substrate disposed between the compression element and the reaction surface.

11. 1. A method for generating an aerosol, comprising: Providing an aerosol substrate between the compression element and the reaction surface of the heating chamber according to any one of claims 1 to 8; operating the heating chamber to raise the temperature of the heating chamber to an aerosol-generating temperature; extracting an aerosol from the heating chamber; operating the heating chamber to reduce the temperature of the heating chamber to an aerosol substrate release temperature; removing the aerosol substrate from the heating chamber; A method comprising:

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