Induction heating cartridge for steam generating device

Abstract

An induction heating cartridge is provided for use with an induction heating assembly. [Solution] The induction-heatable cartridge comprises a solid evaporable material 15 and at least one ring-shaped induction-heatable susceptor 14 held within and surrounded by the evaporable material. The susceptors are held in place such that when the cartridge is positioned in the induction circuit during use, different regions of the outer edges of one or more susceptors are at different distances from the induction circuit, resulting in different heating characteristics within the different regions. The centers of each of the at least one susceptor are aligned along a common axis.

Description

Technical Field

[0001] The present invention relates to an inductively heatable cartridge for a vapor generating device. Devices that heat a substance to generate vapor for inhalation, rather than burning it, have gained popularity among consumers in recent years.

Background Art

[0002] Such devices can use one of a number of different approaches to provide heat to a substance. One such approach is a vapor generating device that utilizes an induction heating system. In such a device, an induction coil (hereinafter also referred to as an inductor) is provided to the device, and a susceptor is provided to the vapor generating substance. When the user activates the device, electrical energy is provided to the inductor, which in turn creates an electromagnetic field. The susceptor couples with the electromagnetic field to generate heat, and the heat is transferred to the substance, and as the substance is heated, vapor is produced.

[0003] Such an approach has the potential to provide better control of heating and thus vapor generation. However, in practice, such an approach often requires a single inductor that generates a common electromagnetic field. This can make it difficult to precisely generate a desired heat profile within the region of the susceptor, and as a result, it is not easily possible to fully control the generation of vapor.

[0004] As the demand for users to be able to generate various vapors from such devices increases, there is a desire for a device that precisely controls the heat profile within the evaporable substance and is lightweight and compact.

[0005] The present invention seeks to mitigate at least some of the above problems.

Summary of the Invention

Means for Solving the Problems

[0006] According to a first aspect of the present invention, an induction-heatable cartridge for use with an induction heating assembly is provided, the cartridge comprising: a solid evaporable material; and at least two ring-shaped induction-heatable susceptors held within and surrounded by the evaporable material, wherein the at least two susceptors are held in place such that, when the cartridge is positioned in an induction circuit during use, different regions of one or more edge portions of each susceptor are at different distances from the induction circuit, resulting in different heating characteristics within the different regions, and the centers of the two or more susceptors are aligned along a common axis.

[0007] According to another aspect of the present invention, there is an induction-heatable cartridge configured to be inserted into a chamber of an induction heating assembly when in use, wherein the chamber is at least partially surrounded by an induction circuit, and the cartridge comprises a solid evaporable material and at least two ring-shaped induction-heatable susceptors held within and surrounded by the evaporable material, wherein the at least two susceptors are held in place such that, when the cartridge is at least partially surrounded by the induction circuit when in use, different regions of the edges of the two or more susceptors are at different distances from the induction circuit, resulting in different heating characteristics within the different regions, and the centers of each of the at least two susceptors are aligned along a common axis.

[0008] In both embodiments, the way in which the heat supplied by the susceptor changes within the cartridge may be referred to as the thermal profile within the cartridge. By having different regions of one or more edge portions of one or more ring-shaped susceptors positioned at different distances from the induction circuit, it is possible to control the thermal profile within the cartridge during use to deliver desired heating to specific regions of the evaporable material.

[0009] One or more edge portions of a ring-shaped susceptor may include an outer edge and an inner edge. Typically, the outer edge of each susceptor may be oriented outward. This is intended to mean that the outwardly oriented edge generally faces outward when viewed from the center of the susceptor and forms the outer circumferential surface of the ring-shaped susceptor. However, the inner edge of each susceptor or each inner edge may be oriented inward. This is intended to mean that the inwardly oriented edge generally faces towards the center of the susceptor and forms the periphery of the hole within the ring-shaped susceptor.

[0010] The outer (or inner) periphery of the ring-shaped susceptor can be of any shape. For example, the outer periphery of the ring-shaped susceptor may be substantially circular. Alternatively, the periphery may be elliptical, convex, wavy, or square. Alternatively, the periphery may be of a random shape. The inner periphery of the ring-shaped susceptor can also be of any shape, and may take any of the shapes described above.

[0011] The susceptor may include, but is not limited to, one or more of the following: aluminum, iron, nickel, stainless steel, and alloys thereof (e.g., nickel-chromium). With the application of an electromagnetic field in its vicinity, the susceptor may generate heat due to eddy currents and magnetic hysteresis losses, which result in an energy conversion from electromagnetic energy to thermal energy.

[0012] The evaporable substance may be any type of solid or semi-solid material. Examples of vapor-generating solids include powders, granules, spheres, flakes, strands, porous materials, or sheets. The substance may include plant-derived materials, and in particular, the substance may include tobacco.

[0013] Preferably, the evaporable substance may contain aerosol-forming compounds. Examples of aerosol-forming compounds include polyhyrdric alcohols such as glycerin or propylene glycol, and mixtures thereof. Typically, the evaporable substance may have an aerosol-forming compound content of approximately 5% to approximately 50% based on dry weight. Preferably, the evaporable substance may have an aerosol-forming compound content of approximately 15% based on dry weight.

[0014] When heated, evaporable substances may release volatile compounds. These volatile compounds may include nicotine or flavor compounds such as tobacco flavorings.

[0015] The cartridge may have any number of two or more susceptors. The cartridge may be configured such that, when the cartridge is positioned within the inductive circuit during use, the edges of at least two susceptors are at different distances from the inductive circuit, resulting in different regions.

[0016] The use of two or more susceptors with edges at different distances from the induction circuit results in a change in the thermal profile between at least two of the susceptors during use.

[0017] Having susceptors that are all the same shape and size may have several advantages (e.g., ease of manufacture and cost reduction), but preferably, each of at least two susceptors may have a different shape and size. If the susceptors are substantially circular, they may have different diameters or holes of different diameters.

[0018] The use of susceptors of different diameters allows for the simple provision of susceptors whose outer edges are at different distances from the induction circuit, while maintaining radial symmetry within the cartridge.

[0019] The common axis connecting the centers of each susceptor can be oriented in any direction. For example, the common axis may be substantially diagonally positioned, so that each ring-shaped susceptor is inclined at a certain angle with respect to the longitudinal axis of the cartridge. Preferably, the common axis is the longitudinal axis of the cartridge. This allows the susceptors to be biased towards one side of the induction circuit, resulting in a change in the distance between different regions of the outer edge, while ensuring that the evaporable material is distributed symmetrically throughout each axial cross-section of the cartridge.

[0020] Alternatively, the longitudinal axis could be the central longitudinal axis. This allows the cartridge to maintain radial symmetry over its entire longitudinal length.

[0021] The cartridge may be placed near or inside an external induction circuit to heat the susceptor, thereby causing the evaporable material to evaporate. The susceptor may be positioned in any configuration relative to the induction circuit, but typically the common axis of the susceptor may be positioned parallel to the axis of the induction circuit when the cartridge is installed inside the induction circuit during use.

[0022] By aligning the common axis parallel to the axis of the induction circuit, power loss from the external electromagnetic field through any orthogonal component of the coupling can be minimized. The improved coupling results in a stronger and more reliable heating effect on the susceptor and, consequently, on the evaporable material.

[0023] The diameter, position, and orientation of each susceptor may be selected according to a set of rules for creating a pattern. For example, the susceptors may be configured to result in an array of susceptors having diameters that gradually decrease in a given direction, where the diameter of each susceptor and / or the diameter of the holes on each susceptor is smaller than that of the preceding one in a given direction, and / or the diameters of the holes that gradually decrease in a given direction.

[0024] The ability to control the heat profile within the cartridge allows different regions of the cartridge to reach different temperatures. The cartridge may include multiple types of evaporable substances such that different solid evaporable substances are positioned around each of at least two different regions. For example, a first evaporable substance may release vapor at a first predetermined temperature and a second evaporable substance may release vapor at a second temperature higher than the first temperature. Different types of evaporable materials may be positioned in specific regions of the cartridge having different heat profiles such that evaporation of each material is optimized.

[0025] The cartridge may comprise any evaporable substance, but preferably the solid material may include tobacco.

[0026] The inductively heatable cartridge may comprise a permeable material in the form of an outer skin or membrane that holds the evaporable substance and the susceptor. The permeable material may be a material that is electrically insulating and non-magnetic. The material may have high air permeability to allow air to flow through the material, along with resistance to high temperatures. Examples of suitable permeable materials include cellulose fibers, paper, cotton, and silk. The permeable material may also serve the role of a filter. Alternatively, the evaporable substance and the susceptor may be held inside a material that does not have air permeability but includes appropriate punched holes or openings to allow air flow.

[0027] According to another aspect of the present invention, there is provided a vapor generation device comprising an inductively heatable cartridge according to the first aspect and an induction heating circuit configured to generate an electromagnetic field that couples with the cartridge during use and produce heat therein.

[0028] By using an inductively heatable cartridge that utilizes a susceptor optimized to generate a desired heat profile within the cartridge, it is possible to provide an efficient vapor generation device having the ability to generate vapor from multiple evaporable substances.

[0029] Typically, the induction circuit can be in the form of a cylindrical coil. The induction coil can include any suitable material, but typically, the induction coil includes a Litz wire or a Litz cable.

[0030] Alternatively, the induction circuit can be in the form of a coil with an irregular shape, whereby it has components at different distances from one or more susceptors within the cartridge, resulting in different heating characteristics in different regions of the cartridge.

[0031] The use of a coil with an irregular shape enables the provision of different distances between the edge of the susceptor and the induction circuit, even when using a susceptor with a regular shape. For example, the diameter of the coil can vary along its longitudinal axis. The variation in the diameter of the coil can be continuous or discontinuous along the longitudinal axis. In such a case, the circuit can have components at different lateral distances from one or more susceptors within the cartridge.

[0032] The device can be configured to operate using a variable electromagnetic field having a magnetic flux density of approximately 0.5 T to approximately 2 T at the highest concentration point during use.

[0033] The device and the circuit mechanism can be configured to operate at a high frequency. Typically, the device and the circuit mechanism can be configured to operate at a frequency of approximately 80 kHz to 500 kHz, preferably approximately 150 kHz to approximately 250 kHz, more preferably 200 kHz.

[0034] The induction circuit can take any form, but preferably, the induction circuit can have a form in which its inner diameter gradually decreases from one side to the other in its axial direction.

[0035] According to another aspect of the present invention, a steam generating device is provided, comprising an induction-heatable cartridge and an induction heating circuit configured to generate an electromagnetic field coupled to the cartridge during use, thereby generating heat inside the cartridge, wherein the induction circuit is in the form of an irregularly shaped coil, so that it has components at different distances from one or more susceptors in the cartridge, resulting in different heating characteristics in different regions of the cartridge.

[0036] By having an induction circuit in the form of an irregularly shaped coil, it is possible to provide a steam generating device capable of generating complex thermal profiles within a regularly or irregularly shaped induction-heatable cartridge. For example, the diameter of the coil may vary along its longitudinal axis. The change in the coil diameter may be continuous or discontinuous. In such cases, the circuit may have components located at different lateral distances from one or more susceptors within the cartridge.

[0037] The susceptor can take any shape, but preferably it can take a ring-shaped form.

[0038] The inductive circuit can take any form, but preferably, it may have a form in which its inner diameter gradually decreases from one side to the other in the axial direction.

[0039] Exemplary induction heating assemblies and exemplary induction heating cartridges are described in detail below with reference to the accompanying drawings. [Brief explanation of the drawing]

[0040] [Figure 1] Figure 1 schematically shows a steam generation device according to an example of the present invention. [Figure 2] Figure 2 shows a schematic exploded view of the steam generation device shown in Figure 1. [Figure 3] Figure 3 shows a schematic cross-sectional view through the steam generation device shown in Figures 1 and 2. [Figure 4]Figure 4 schematically shows an induction-heatable cartridge held within an induction circuit according to an example of the present invention. [Figure 5A] A schematic example of an induction-heatable cartridge according to the present invention, held within an induction circuit, is shown. [Figure 5B] A schematic example of an induction-heatable cartridge according to the present invention, held within an induction circuit, is shown. [Figure 5C] A schematic example of an induction-heatable cartridge according to the present invention, held within an induction circuit, is shown. [Figure 5D] A schematic example of an induction-heatable cartridge according to the present invention, held within an induction circuit, is shown. [Figure 6A] Further schematic examples of the induction-heatable cartridge according to the present invention, held within an induction circuit, are shown. [Figure 6B] Further schematic examples of the induction-heatable cartridge according to the present invention, held within an induction circuit, are shown. [Figure 7] Further schematic examples of the induction-heatable cartridge according to the present invention, held within an induction circuit, are shown. [Figure 8] Further schematic examples of the induction-heatable cartridge according to the present invention, held within an induction circuit, are shown. [Modes for carrying out the invention]

[0041] The present invention provides a steam generating device that utilizes a cartridge including an induction heating system and an induction-heatable susceptor that provides the ability to generate a desired thermal profile within the cartridge during use.

[0042] Figures 1 and 2 schematically show a steam generation device according to an example of the present invention. The exemplary device is shown overall in an assembled configuration in Figure 1 and in an unassembled configuration in Figure 2.

[0043] An exemplary steam generating device 1 is a handheld device (wherein we intend to mean a device that a user can hold and support with one hand without assistance) and comprises an induction-heatable cartridge 13 and an induction heating circuit 12. When the cartridge 13 is heated, steam is released from the cartridge 13. During use, steam is generated by heating the induction-heatable cartridge 13 using an induction heating assembly 11. The steam is then available for inhalation by the user.

[0044] An air inlet 22, positioned adjacent to the induction-heatable cartridge 13, supplies air to the cartridge 13 from the surrounding environment. An air outlet 23 is in gas communication with the cartridge 13 and provides the ability to extract vapor generated from the cartridge 13 during use. In this example, device 1 further comprises a mouthpiece 24 in communication with the air outlet 23. The mouthpiece 24 provides the user with the ability to easily inhale vapor generated from device 1. During use, the user inhales vapor by drawing air into device 1 while the cartridge 13 is heated, passing it through or surrounding the induction-heatable cartridge 13, and exiting through the mouthpiece 24. Air is typically drawn through device 1 by the application of negative pressure created when the user inhales air from the air outlet 23.

[0045] Cartridge 13 is a body containing an evaporable substance 15 and an induction-heatable susceptor mechanism 14. In this example, the evaporable substance 15 includes one or more of tobacco, a humectant, glycerin, and propylene glycol. The susceptor mechanism 14 includes a plurality of conductive plates 14. In this example, cartridge 13 also has an air-permeable layer or membrane 16 to contain the evaporable substance 15 and the susceptor 14. In other examples, the membrane 16 is absent.

[0046] As described above, the induction heating assembly 11 is used to heat the cartridge 13. The assembly 11 includes an induction heating device in the form of an induction circuit 12 and a power supply (not shown in the figure). The power supply and the induction circuit 12 are electrically connected so that power can be transmitted between the two components.

[0047] In this example, both the induction circuit 12 and the cartridge 13 are substantially cylindrical. Figure 3 schematically shows a top-down cross-sectional view of device 1 through line AA. The cross-section includes the region of the induction heating circuit 12 and the induction-heatable cartridge 13 held within the induction circuit 12.

[0048] Starting from the outermost part of the cross-section, the induction heating circuit 12 includes an annular housing for an induction circuit having a circular cross-section. An induction-heatable cartridge 13 is held in place within the internal region of the annular housing. In this example, the region of the cartridge 13 is defined by an air-permeable outer shell 16 (or membrane), which also has a circular cross-section. The outer shell 16 contains an evaporable substance 15 and a ring-shaped induction-heatable susceptor 14 held within and surrounded by the evaporable substance 15. Each of the ring-shaped susceptors 14 is a closed circuit in itself, positioned so that its center is substantially aligned with the center of the induction heating circuit 12. The susceptors 14 are in contact with the evaporable substance 15 surrounding the susceptors 14 from all sides.

[0049] During use, the application of an electromagnetic field from the induction circuit 12 causes the susceptor 14 to heat up. The heat from the susceptor 14 causes the surrounding evaporable material 15 to evaporate, thereby generating steam.

[0050] Since the susceptor 14 is heated by induction heating, which requires the transmission of power through an electromagnetic field, in most situations, reducing the distance between the susceptor 14 and the induction circuit 12 increases the heating effect.

[0051] Figure 4 schematically shows a close-up view of an exemplary induction-heatable cartridge 13 held within a portion of the induction circuit 12, and the distance between the outer edge of the susceptor 14 and the induction circuit 12 is shown.

[0052] In this example, the distance between the outer edge of the susceptor and the induction circuit (distance A in Figure 4) is defined as the shortest radial distance between the outer edge of the susceptor and the inner edge of the induction circuit 12. The outer edge of the susceptor 14 is defined as the region of the susceptor 14 immediately in the vicinity of a point on the periphery of the susceptor 14. This distance determines the degree of heat generated at the outer edge of the susceptor 14. As mentioned above, due to the fact that electromagnetic coupling improves with shorter distances, shorter distances result in greater heat generation at the edge of the susceptor 14.

[0053] To control the heat generated at each edge, the distance between the (outer and / or inner) edges of the susceptor 14 and the induction circuit 12 can be changed. In other words, the thermal profile generated from the edges of the susceptor 14 can be selected by appropriately setting their distances from the induction circuit 12. By using multiple ring-shaped susceptors 14 with different such distances (not explicitly shown in Figures 1-4), as shown in Figure 4, it is possible to precisely generate a desired thermal profile within the inductively heatable capsule 13 by applying a substantially uniform inductive electromagnetic field. As a result, relatively complex phenomena can be created using a simple dimensional design configuration within the consumables.

[0054] Next, we describe an exemplary configuration of the cartridge and inductive circuit with reference to the diagram. The illustrated example includes three susceptors, which is for illustrative purposes to illustrate the characteristics of each mechanism. In other examples, the cartridge may include any number of susceptors.

[0055] Figure 5A schematically shows an exemplary cartridge 53 held within the induction circuit 52. The cartridge 53 is substantially cylindrical and has a base surface at the axial end of the cartridge, a top surface at the opposite axial end of the cartridge, and a peripheral surface. The cartridge 53 comprises a frustoconical body of evaporable material 55 that tapers toward the base surface of the cartridge 53. Three ring-shaped susceptors 54 are held within and surrounded by the evaporable material 55. The susceptors 54 are configured such that the center of each susceptor 54 is substantially aligned with the central longitudinal axis of the induction circuit 52.

[0056] Starting with the susceptor closest to the top surface of the cartridge 53, the uppermost ring-shaped susceptor 54a has a first diameter, the middle ring-shaped susceptor 54b has a second diameter smaller than the first diameter, and the lowermost ring-shaped susceptor 54c has a third diameter smaller than the second and first diameters.

[0057] The air-permeable outer shell 56 substantially surrounds the evaporable material 55. The outer shell 56 provides structural support for holding the evaporable material 55 while allowing air and vapor to pass through by diffusion.

[0058] The induction circuit 52 substantially surrounds the peripheral surface of the cartridge 53. The internal morphology of the housing for the induction circuit has a shape complementary to the shape of the induction cartridge 53. This allows the cartridge 53 to be inserted and held in place by the induction device 51. Because the susceptors 54 have different diameters, their outer edges are at different distances from the surrounding induction circuit 52. For example, the uppermost susceptor 54a, which has the largest diameter, has its outer edge at the shortest distance from the induction circuit 52.

[0059] In this example, the outer edge of the uppermost susceptor 54a is at least locally surrounded by a first type of evaporable material 55a suitable for heating at a first temperature. The outer edge of the lowermost susceptor 54c is at least locally surrounded by a second type of evaporable material 55b suitable for heating at a second temperature lower than the first temperature.

[0060] During use, the application of an electromagnetic field from the induction circuit 52 generates heat in each susceptor 54. As described above, the smaller the distance between the induction circuit 52 and the outer edge of the susceptor 54, the greater the amount of heat generated at that edge. The induction circuit 52 generates a substantially uniform electromagnetic field along its longitudinal axis, but the heat generated in the outer region of each susceptor 54 differs, resulting in a non-uniform heating effect along the longitudinal axis of the cartridge 53. As a result, different regions of the cartridge 53 are heated to different temperatures by applying only a single electromagnetic field from the induction circuit 52.

[0061] When the induction circuit 52 is switched on, vapor of the first evaporable substance 55a is generated at the outer edge of the uppermost susceptor 54a, and vapor of the second evaporable substance 55b is generated at the outer edge of the lowermost susceptor 54c. In this way, the cartridge 53 provides the ability to simultaneously generate a vapor mixture from two different evaporable substances using a single induction circuit 52.

[0062] The air-permeable outer shell 56 maintains the frustoconical shape of the evaporable material 55, while the shape of the cartridge 53 is cylindrical. In another example, as shown in Figure 5B, the air-permeable outer shell 56 has a substantially cylindrical external morphology and an internal taper to complement the frustoconical volume of the evaporable material 55. This allows air drawn in from the air inlet 22 to be distributed across the entire surface of the evaporable material 55, increasing the supply of air for ventilation and evaporation.

[0063] Another example of an induction-heatable cartridge, schematically shown in Figure 5C, is similar to the cartridge described above with reference to Figure 5A. In this example, the frustro-conical body of the evaporable substance 55 is instead tapered towards the top surface of the cartridge 53, and the three ring-shaped susceptors 54' gradually increase in diameter from the uppermost susceptor 54a' to the lowermost susceptor 54c'. As a result, more heat is generated at the outer edge of the lowermost susceptor 54c' during use.

[0064] In another example, as shown in Figure 5D, the air-permeable outer shell 56 has a substantially cylindrical external shape and an internal taper to complement the frustoconical volume of the evaporable material 55. As described above, this increases ventilation and the supply of air to the evaporable material.

[0065] Figure 6A schematically shows an exemplary cartridge 63 held within the induction circuit 62. The cartridge is cylindrical and has a base surface at the axial end of the cartridge 63, a top surface at the opposite axial end of the cartridge 63, and a peripheral surface. The cartridge 63 comprises a cylindrical body of evaporable material 65. Three ring-shaped susceptors 64 are held within and surrounded by the evaporable material 65. The susceptors 64 are configured such that the center of each susceptor 64 aligns with the central longitudinal axis of the cartridge 63. In this example, the susceptors 64 have substantially the same diameter.

[0066] The air-permeable outer shell 66 substantially encloses the evaporable material 65. The outer shell 66 provides structural support for holding the evaporable material 65 while allowing air and vapor to pass through by diffusion.

[0067] The induction circuit 62 substantially surrounds the peripheral surface of the cartridge 63. In this example, the induction circuit 62 is a coil wound such that its radiating diameter increases from the upper axial end to the lower axial end, so that the coil 62 is substantially frustoconical in shape. In this configuration, all susceptors 64 have substantially the same diameter, but the distance between the outer edge of each susceptor 64 and the induction circuit 62 gradually increases from the uppermost susceptor 64a to the lowermost susceptor 64c.

[0068] Due to the difference in distance, the induction circuit 62 generates an uneven electromagnetic field along its longitudinal axis during use. Consequently, the most heat is generated at the outer edge of the uppermost susceptor 64a, while less heat is generated at the outer edge of the lowermost susceptor 64c.

[0069] As described above, this difference in the heat generated can be utilized by using two or more different types of evaporable materials 65. In this example, the outer edge of the uppermost susceptor 64a is at least locally surrounded by a first type of evaporable material 65a that is suitable for heating at a first temperature. The outer edge of the lowermost susceptor 64c is at least locally surrounded by a second type of evaporable material 65b that is suitable for heating at a second temperature lower than the first temperature.

[0070] When the induction circuit is switched on, vapor of the first evaporable substance 65a is generated at the outer edge of the uppermost susceptor 64a, and vapor of the second evaporable substance 65b is generated at the outer edge of the lowermost susceptor 64c. In this way, the cartridge 63 provides the ability to simultaneously generate a vapor mixture from two different evaporable substances using a single induction circuit 62.

[0071] Another example of an induction-heatable cartridge, schematically shown in Figure 6B, is similar to the cartridge described above with reference to Figure 6A. In this example, the induction coil 62' is wound such that its diameter decreases from the upper axial end to the lower axial end, so that the coil 62' is substantially frustoconical in shape and tapers towards the base. In this configuration, more heat is generated at the outer edge of the lowest susceptor 64c' during use.

[0072] Figure 7 shows another exemplary cartridge 73 held within the induction circuit 72. The cartridge 73 is cylindrical and has a base surface at the axial end of the cartridge 73, a top surface at the opposite axial end of the cartridge 73, and a peripheral surface. The cartridge 73 comprises a cylindrical body of evaporable material 75. Three ring-shaped susceptors 74 are held within and surrounded by the evaporable material 75. The susceptors 74 are configured such that the center of each susceptor 74 is aligned along the longitudinal axis of the cartridge 73. The longitudinal axis is offset from the central axis of the induction circuit 72. In this example, the susceptors 74 have substantially the same diameter.

[0073] Since each susceptor 74 is substantially aligned along an axis off-center from the center of the induction circuit 72, different regions of their outer edges are at different distances from the induction circuit 72. For example, in the cross-section shown in Figure 7, the susceptors 74 are aligned closer to the left side of the induction circuit 72. In this configuration, the outer edge of the left end of the susceptor 74 is closer to the induction circuit 72 than the outer edge of the right end, and as a result, the heat generated at the outer edge of the left end during use is greater than the heat generated at the outer edge of the right end.

[0074] As described above, this difference in heat generation can be utilized by using two or more different types of evaporable materials. In this example, the left outer edge of the susceptor 74 is locally surrounded by a first type of evaporable material 75a that is suitable for heating at a first temperature. The right outer edge of the susceptor 74 is locally surrounded by a second type of evaporable material 75b that is suitable for heating at a second temperature lower than the first temperature.

[0075] When the induction circuit 72 is switched on, vapor of the first evaporable substance 75a is generated at the outer edge of the left end of each susceptor 74, and vapor of the second evaporable substance 75b is generated at the outer edge of the right end of each susceptor 74. In this way, the cartridge 73 provides the ability to simultaneously generate a vapor mixture from two different evaporable substances using a single induction circuit 72.

[0076] Figure 8 shows another exemplary cartridge 83 held within the induction circuit 82. The cartridge 83 is cylindrical and has a base surface at the axial end of the cartridge 83, a top surface at the opposite axial end of the cartridge 83, and a peripheral surface. The cartridge 83 comprises a cylindrical body of evaporable material 85. Three ring-shaped susceptors 84 are held within and surrounded by the evaporable material 85. The susceptors 84 are configured such that the center of each susceptor 84 is aligned along the longitudinal axis of the cartridge 83. In this example, the uppermost susceptor 84a and the lowermost susceptor 84c both have a first diameter, while the central susceptor 84b has a second diameter smaller than the first diameter.

[0077] In this configuration, the uppermost susceptor 84a and the lowermost 84c have their outer edges at a first distance from the induction circuit 82, while the central susceptor 84b has its outer edge at a second distance from the induction circuit 82, which is greater than the first distance.

[0078] During use, the heat generated at the outer edges of the uppermost susceptor 84a and the lowermost susceptor 84c is greater than the heat generated at the outer edge of the central susceptor 84b. As described above, this difference in generated heat can be utilized by using two or more different types of evaporable materials 85. In this example, the outer edges of the uppermost susceptor 84a and the lowermost susceptor 84c are locally surrounded by a first type of evaporable material 85a suitable for heating at a first temperature, and the outer edge of the central susceptor 84b is locally surrounded by a second type of evaporable material 85b suitable for heating at a second temperature lower than the first temperature.

[0079] When the induction circuit 82 is switched on, vapor of the first evaporable substance 85a is generated at the outer edges of the uppermost susceptor 84a and the lowermost susceptor 84c, and vapor of the second evaporable substance 85b is generated at the outer edge of the central susceptor 84b. In this way, the cartridge 83 provides the ability to simultaneously generate a vapor mixture from two different evaporable substances using a single induction circuit 82.

[0080] In this example, the susceptor 84 is aligned along the central longitudinal axis of the induction circuit 82, but in other examples, the susceptor 84 is aligned along a longitudinal axis that is off-center from the center of the induction circuit 82.

[0081] As can be understood from the above, the present invention enables the provision of a steam generation device capable of generating complex steam from multiple evaporable materials by installing at least two ring-shaped induction-heatable susceptors having different regions of their outer edges at different distances from the induction circuit. Furthermore, by changing the mechanism, dimensions, or alignment of the susceptors in the consumables, it is possible to provide different user experiences for different types of consumables when used with a common device. An electronic steam generation device having a safe heating mechanism for generating a desired thermal profile is achieved by the present invention while maintaining the compactness and portability of such a steam generation device.

Claims

1. An induction-heatable cartridge configured to be inserted into the chamber of an induction heating assembly when in use, wherein the chamber is at least partially surrounded by an induction circuit, and the cartridge is Solid evaporable substances and, A cartridge comprising: at least two ring-shaped induction-heatable susceptors held within and surrounded by the evaporable material, wherein the at least two susceptors are held in a fixed position such that, when the cartridge is at least partially surrounded by the induction circuit during use, different regions of the edges of the two or more susceptors are at different distances from the induction circuit, resulting in different heating characteristics within the different regions, and the centers of each of the at least two susceptors are aligned along a common axis.

2. The cartridge according to claim 1, comprising at least two susceptors, each of which is configured to have a different shape or size from the other two susceptors.

3. The cartridge according to claim 1, wherein each of the at least two susceptors is substantially circular and the at least two susceptors have different diameters.

4. The cartridge according to any one of claims 1 to 3, wherein the common axis is the longitudinal axis of the cartridge.

5. The cartridge according to claim 4, wherein the common axis is the longitudinal axis of the center of the cartridge.

6. The cartridge according to any one of claims 1 to 5, wherein the axis of alignment of the susceptors is arranged to be parallel to the axis of the induction circuit when the cartridge is installed in the induction circuit during use.

7. The cartridge according to any one of claims 1 to 6, wherein the diameter of each susceptor is smaller than that of the preceding one in a given direction, resulting in an array of susceptors with progressively smaller diameters.

8. The cartridge according to any one of claims 1 to 7, wherein different solid evaporable materials are positioned around each of the at least two different regions.

9. The cartridge according to claim 8, wherein the first material releases vapor at a first predetermined temperature, and the second material releases vapor at a second temperature higher than the first temperature.

10. The cartridge according to any one of claims 1 to 9, wherein the solid material includes tobacco.

11. An induction heating cartridge according to any one of claims 1 to 10, An induction heating circuit is configured to generate an electromagnetic field that connects with the cartridge during use, thereby generating heat inside it. A steam generating device equipped with the following features.

12. The steam generating device according to claim 11, wherein the induction circuit is in the form of a cylindrical coil.

13. The steam generating device according to claim 11, wherein the induction circuit is in the form of a coil having a diameter that varies in the longitudinal direction, so that the circuit has components at different lateral distances from one or more susceptors in the cartridge, resulting in different heating characteristics in the different regions of the cartridge.

14. The steam generating device according to any one of claims 1 to 13, wherein the induction circuit has a configuration in which its inner diameter gradually decreases from one side to the other in the axial direction.

15. A steam generating device, Induction heating cartridge, An induction heating circuit is configured to generate an electromagnetic field that connects with the cartridge during use, thereby generating heat inside it. Equipped with, A steam generating device in which the induction circuit is in the form of a coil having a diameter that varies in the longitudinal direction, thereby having components at different lateral distances from one or more susceptors in the cartridge, resulting in different heating characteristics in the different regions of the cartridge.

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