Electromagnetic induction heating assembly for steam generating device

Abstract

To provide a heating assembly for a vapor generating device to perform proper temperature monitoring and / or control.SOLUTION: The heating assembly comprises: an induction coil 16, radially inward of which a heating compartment is defined for receiving, in use, a body comprising a vaporizable substance 22 and an induction-heatable susceptor 24; and a temperature sensor 11 located to face a side of the heating compartment on a central longitudinal axis of the induction coil at an end of the heating compartment, where the induction coil in use heats the susceptor, and the temperature sensor in use monitors a temperature related to heat generated from the susceptor.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an electromagnetic induction heating assembly for a steam generating device. [Background technology]

[0002] Devices that heat, rather than burn, substances to produce a vapor for inhalation have become popular with consumers in recent years.

[0003] Such devices can provide heat to the substance using one of several different methods, one of which is to simply provide a heating element that is powered to heat the element, which in turn heats the substance to produce vapor.

[0004] One way to achieve such steam generation is to provide a steam generating device that employs electromagnetic induction heating. In such a device, an electromagnetic induction coil (hereinafter also referred to as an inductor and an electromagnetic induction heating device) is provided in the device, and a susceptor is provided with a steam generating material. When a user activates the device, electrical energy is supplied to the inductor, which in turn generates an electromagnetic (EM) field. The susceptor couples with the field and generates heat, which is transferred to the material, which heats up and generates steam.

[0005] The use of electromagnetic induction heating to generate steam can provide controlled heating and therefore controlled steam generation. In practice, however, such approaches can unintentionally result in improper temperatures in the steam generating material. This can waste power, increase operating costs, damage components or make inefficient use of the steam generating material, and inconvenience users who expect a simple and reliable device.

[0006] This has traditionally been addressed by monitoring the temperature within the device. Proper temperature monitoring and / or control is also important as this prevents overheating or combustion of the materials used to generate the steam. However, it has been found that these temperatures are unreliable and do not represent the actual temperatures generated, further reducing the reliability of such devices.

[0007] The present invention seeks to overcome at least some of the problems set forth above. Summary of the Invention [Means for solving the problem]

[0008] According to a first aspect, there is provided an electromagnetic induction heating assembly for a steam generating apparatus comprising: an electromagnetic induction coil defining a heating compartment radially inwardly thereof for accommodating, in use, an object comprising a vaporizable substance and an electromagnetically inductively heatable susceptor; and a temperature sensor positioned facing a side of the heating compartment on a central longitudinal axis of the electromagnetic induction coil at an end of the heating compartment, the electromagnetic induction coil adapted to heat the susceptor in use, and the temperature sensor adapted to monitor a temperature associated with heat generated from the susceptor in use.

[0009] (Note that the term sides of a heating compartment is used herein to include the axial ends of the heating compartment.)

[0010] It has been found that locating the electromagnetic induction coil in this position achieves a good balance between the ability to accurately measure the temperature and reducing noise in the signal generated by the temperature sensor caused by the EM field generated by the electromagnetic induction coil. This therefore increases the accuracy of the monitored temperature while also increasing the precision of the monitored temperature, and therefore provides an optimal position for locating the temperature sensor. By moving the temperature sensor away from where heat is generated and providing a gap between the sensor and the source of the EM field, the noise in the signal generated by the temperature sensor may increase the precision of the monitored temperature. However, this reduces the precision of the monitored temperature because the temperature sensor is away from where heat is generated. On the other hand, locating the temperature sensor in the axial center of the electromagnetic induction coil increases the amount of noise due to the greater strength of the EM field at that location. This therefore increases the likelihood that the monitored temperature will represent the temperature achieved by heating, but reduces the precision that can be achieved.

[0011] The phrase "disposed against a side of" in reference to a heating compartment as described above is intended to mean that the temperature sensor is disposed on a side of the heating compartment. For example, the phrase is intended to mean that all parts of the temperature sensor may be closer to the side of the heating compartment than to the center of the heating compartment or to a plane parallel to the side of the heating compartment that passes through the center of the heating compartment.

[0012] The susceptor may include, but is not limited to, one or more of aluminum, iron, nickel, stainless steel, and alloys thereof (e.g., nickel-chromium). Application of an electromagnetic field in the vicinity of the susceptor can cause the susceptor to generate heat due to eddy currents and magnetic hysteresis losses resulting in energy conversion from electromagnetic to thermal.

[0013] The electromagnetic induction coil may have any shape capable of providing heat to the susceptor during use. Typically, the electromagnetic induction coil is cylindrical. This provides an EM field with improved field uniformity radially inward of the coil compared to fields that can be generated using other coil shapes. This results in more uniform heating and allows temperature monitoring to be more representative of the object's temperature. This also provides stronger coupling between the EM field and the susceptor, making heating more efficient.

[0014] Preferably, the temperature sensor may simply be located between the axial center of the electromagnetic induction coil and the axial end of the electromagnetic induction coil. This places the temperature sensor inside the area where heat is effectively generated thanks to the strong coupling between the susceptor and the EM field. Also, the strength of the EM field is lower than at the axial center of the electromagnetic induction coil. This makes the monitored temperature more representative of the temperature generated by heating, and therefore more accurate, since the interference of the EM field is smaller. Also preferably, the axial end of the electromagnetic induction coil may be the axial end closest to the side of the heating compartment opposite which the temperature sensor is located.

[0015] The temperature sensor may simply be preferably located at the axial end of the electromagnetic induction coil, or approximately at the axial end of the electromagnetic induction coil, such as any point moved from the axial end of the electromagnetic induction coil toward or away from the center of the electromagnetic induction coil by up to a quarter of the length of the electromagnetic induction coil. Locating the sensor beyond the axial end of the electromagnetic induction coil further reduces the amount of noise in the signal generated by the temperature sensor, since the interaction between the temperature sensor and the EM field decreases with increasing distance from the axial center of the electromagnetic induction coil.

[0016] Additionally or alternatively, the temperature sensor may be located within the heating compartment or may protrude into the heating compartment, such that the temperature sensor is located within the area in which the object is placed, such that the object surrounds the temperature sensor when placed in the heating compartment, such that the temperature sensor provides a more representative monitored temperature, since the temperature sensor is located within the environment in which heat is generated and is surrounded by the material through which heat is transferred during heating.

[0017] The cross-sectional area of ​​the temperature sensor perpendicular to the axial direction of the coil is 10.0 square millimeters (mm 2 ) or less, preferably 7.0 mm 2 Less than 2.5mm, preferably 2 This results in the temperature sensor receiving less exposure to the EM field, thus reducing noise.

[0018] The assembly may be adapted, during use, to operate with a varying electromagnetic field having a magnetic flux density of between about 0.5T and about 2.0T at the point of highest density.

[0019] The power supply and circuitry may be configured to operate at high frequencies, preferably between about 80 kHz and 500 kHz, preferably between about 150 kHz and 250 kHz, more preferably at about 200 kHz.

[0020] The electromagnetic induction coil may comprise any suitable material, but typically the electromagnetic induction coil may comprise a Litz wire or a Litz cable.

[0021] According to a second aspect of the present invention there is provided an electromagnetically heatable cartridge for use with an electromagnetic induction heating assembly according to any one of the preceding claims, the cartridge comprising a solid vaporizable substance and an electromagnetically heatable susceptor carried by the vaporizable substance, the electromagnetically heatable susceptor being planar and having an edge around a periphery of the susceptor, wherein a total length of the edge of the susceptor in a central region of the cartridge having a first area is longer than a total length of the edge of the susceptor in any of a plurality of outer regions of the cartridge, each of the plurality of outer regions having the same shape and orientation as the central region and an area equal to the first area, the outer regions may extend radially beyond the outer periphery of the cartridge, preferably the central region and the plurality of outer regions form a continuous array, the outer periphery of the array encompassing the outer periphery of the cartridge.

[0022] When heat is being generated in the susceptor, the majority of the heat is generated at the edge of the susceptor. By having a solid vaporizable material, the susceptor is held in place inside the cartridge. This makes the distribution of heat during heating predictable and repeatable, since the edge does not move, which may happen if the vaporizable material is liquid, as it is depleted by heating. The cartridge of the second embodiment combines a longer overall length of the inwardly facing edge than the outwardly facing edge, concentrating the heating in the center of the cartridge, which is heated evenly. This makes temperature monitoring using the electromagnetic induction heating assembly according to the first embodiment more accurate, since concentrating the heating in this area means that the heat is generated at a minimum distance from the temperature sensor.

[0023] By the phrase "inwardly facing edge" it is intended to mean that this edge generally faces towards the centre of the susceptor. This means that typically the inwardly facing edge does not form part of the outer periphery of the susceptor. When the susceptor is placed in a heating compartment (inside a cartridge), this inwardly facing edge is intended to be the edge that faces away from the nearest part of the electromagnetic induction coil. Typically, such an inner edge may surround an opening in the centre of a planar ring shaped susceptor element.

[0024] An "outward facing edge" is intended to be the opposite of an inward facing edge. By this phrase, an outward facing edge is intended to mean generally facing away from the center of the susceptor. This typically means that the outward facing edge forms part of the outer periphery of the susceptor. When placed in a heating compartment, this outward facing edge is intended to be the edge that faces the nearest portion of the electromagnetic induction coil.

[0025] The total length of the edges within a unit area is sometimes referred to as the edge density. Thus, it is contemplated that there will be a higher edge density of the inwardly facing edges of the susceptor in the central region than the outwardly facing edges of the susceptor in the outer regions.

[0026] The array referred to in relation to the second embodiment may be a planar array. The array may be parallel to the susceptor or susceptor plate.

[0027] By the term "encompassing" it is intended to mean that the area of ​​the array is at least as large as and overlaps with the area of ​​the cartridge. In other words, it is intended to mean that the minimum distance from one end of the array to the other is at least equal to the minimum distance from one end of the cartridge to the other at its widest point. Of course, the widest point is intended to be the widest point in a plane parallel to the plane of the array and / or susceptor / susceptor plate.

[0028] By the phrase "outer periphery of the cartridge" it is intended to mean the periphery of the cartridge at its greatest part in a plane parallel to the plane of the array and susceptor / susceptor plate.

[0029] The susceptor can be of any shape that provides the inward and outward facing edges as described above. Typically, the susceptor has an opening in the central region. This allows more heat to be generated in the center of the susceptor, further improving the accuracy of the monitored temperature because the heat has a shorter distance to dissipate before it is detected by the temperature sensor.

[0030] The first area may be less than a total area of ​​the susceptor (or individual susceptor plate). Further, a center point of the susceptor (or individual susceptor plate) may be outside of each outer region.

[0031] The central and outer regions may form elements in an array or regular grid defined within an area encompassing a cross section of the cartridge in a plane parallel to the susceptor or individual susceptor plates. In particular, the central and outer regions may comprise a 3×3 rectangular array (with congruent sides, the rectangles may be squares), the central one forming the central region and the other eight surrounding regions forming the outer region, the outer boundary of the array being selected to be as small as possible so as to completely bound the outer edge of the cartridge. Alternatively, the outer boundary of the array may be selected to be as small as possible so as to completely bound the outer edge of the smallest circle that bounds the cross section of the cartridge (e.g., by connecting the vertices of a regular polygon).

[0032] If the cross section is substantially circular, the central and outer regions may be determined as follows: A square is defined by four lines. Each of the four lines is a tangent to the circular cross section of the cartridge. The inner region of the square is separated into three equal parts by two further lines, the two further lines being parallel to two sides of the square. The inner region of the square is also separated into three equal parts by two further lines parallel to the other two sides of the square. This results in nine equally sized and equally shaped parts of the square. The area bounded by the four further lines is the central region. Each other part is an outer region.

[0033] If the cross section is substantially a regular polygon, the central region and the outer regions may be determined as follows: A circle is defined connecting the vertices of the regular polygonal cross section of the cartridge. Four lines define a square. Each of the four lines is a tangent to said circle. The inner region of the square is separated into three equal parts by two further lines, the two further lines being parallel to two sides of the square. The inner region of the square is also separated into three equal parts by two further lines parallel to the other two sides of the square. This results in nine equally sized and equally shaped parts of the square. The area bounded by the four further lines is the central region. Each other part is an outer region.

[0034] If the cross section is substantially elliptical, the central and outer regions may be determined as follows: A rectangle is defined by four lines. Each of the four lines is a tangent to the elliptical cross section of the cartridge. Two of the tangents are parallel to the longest straight line intersecting the center point of the ellipse, and the other two tangents are parallel to the shortest straight line intersecting the center point of the ellipse (and perpendicular to said longest straight line). The inner region of this rectangle is separated by two further lines parallel to the longest straight line into three equal parts between the two lines parallel to the longest straight line. The inner region of this rectangle is also separated by two further lines parallel to the shortest straight line into three equal parts between the two lines parallel to the shortest straight line. This results in nine equally sized and equally shaped parts of the rectangle. The area enclosed by the two further lines parallel to the longest straight line and the two further lines parallel to the shortest straight line is the central region. Each other part is an outer region.

[0035] Each of the central and outer regions may have edges of any length therein. Typically, the central region will have a total composite edge length greater than the total composite edge length in any of the outer regions (or at least greater than the average total composite edge length in all of the outer regions), where the composite edge (or composite edge portion) includes an inwardly facing edge portion and an outwardly facing edge portion. This is advantageous because more heat will be generated in the central region. This will result in more heat being generated closer to the temperature sensor during heating in use. This will allow the monitored temperature to be more representative of the temperature achieved by heating, and therefore more accurate.

[0036] The susceptor can take any form suitable for heating the vaporizable material. Typically, the susceptor includes multiple plates arranged in parallel planes perpendicular to the main central axis of the electromagnetic induction coil. This improves the distribution of heat generated at the susceptor edges by positioning the susceptor parts at multiple locations in the vaporizable material.

[0037] The plates of the susceptor (interchangeably referred to as plates and susceptor plates) may be arranged in any manner suitable for heating the vaporizable material. In some embodiments, each plate may take the form of a disk, or a ring, or a portion of a similar shape, each arranged with a radial separation between the plate and the center point of the central region. This provides good coupling between the susceptor plate and the EM field, while at the same time minimizing the coupling of the EM field at the center point of the central region. This reduces the amount of energy absorbed at the center point of the central region by increasing the amount of energy absorbed away from the center point, thereby minimizing the noise at the center point, thereby reducing the noise at the temperature sensor. This is because the temperature sensor and the center point are aligned along the central longitudinal axis of the heating compartment of the first embodiment. By reducing the amount of energy absorbed at the center point, as well as along the central longitudinal axis of the electromagnetic induction coil (which is also achieved), the amount of electromagnetic induction heating of the temperature sensor is also minimized.

[0038] Additionally, the plates may be oriented in any manner that provides a separation between each plate and the center point of the central region. Typically, the plates are oriented in a plane that is disposed to completely surround the center point of the central region. This results in a higher density of inwardly facing edges in the central region than outwardly facing edges in the outer regions, while distributing the inwardly facing edges over multiple planes. This improves heat distribution by spreading out the portion of the susceptor plate that generates the majority of the heat.

[0039] By the term "surrounding" it is intended to mean that for a plane connecting all of the susceptor plates (even though the susceptor plates may be located at different levels within the cartridge, as shown in Figures 7 and 8), the plates surround the central point in at least two dimensions such that the central point is enclosed within that plane.

[0040] Preferably, each plane may include one plate or two plates, and in the case of a plane including one plate, there may be a further plane including a plate arranged opposite the center point of the central region, and in the case of a plane including two plates, there may be a separation between each plate, each plate being arranged opposite each other from the center point of the central region. It has been found that these arrangements of susceptor plates provide a high edge density of inwardly facing edges in the central region that are distributed among the vaporizable material, thus improving the distribution of heat as it is generated.

[0041] The plates in each plane may be oriented in any suitable manner relative to one another to distribute heat evenly, even with vaporizable materials. Typically, in each plane containing two plates, the plates in each plane are oriented differently than the plates in each other plane containing two plates, and preferably each plane contains two plates. This results in a more even distribution of heat, even with vaporizable materials, reducing the possibility of hot or cold spots.

[0042] The vaporizable material may include any ingredient suitable for producing a vapor to be inhaled by a user. Typically, the vaporizable material includes tobacco, a humectant, glycerin, and / or propylene glycol.

[0043] The vaporizable substance is any type of solid or semi-solid material. Examples of types of vapor-generating solids include powders, granules, pellets, pieces, strands, porous materials, or sheets. The substance may include plant-derived materials, and in particular the substance may include tobacco.

[0044] Preferably, the vaporizable material may include an aerosol former. Examples of aerosol formers include polyhydric alcohols such as glycerin or propylene glycol and mixtures thereof. Typically, the vaporizable material may include an aerosol former content of between about 5% and about 50% on a dry weight basis. Preferably, the vaporizable material may include an aerosol former content of about 15% on a dry weight basis.

[0045] Upon heating, the vaporizable material may release volatile compounds, which may include nicotine or flavor compounds, such as tobacco flavorings.

[0046] The cartridge may include a breathable shell in which the vaporizable substance is placed during use. The breathable material may be an electrically insulating and non-magnetic material. The material may have high breathability and allow air to flow through the material with resistance to high temperatures. Examples of suitable breathable materials include cellulose fibers, paper, cotton, and silk. The breathable material may also act as a filter. Alternatively, the object may be a vaporizable substance wrapped in paper. Alternatively, the object may be a vaporizable substance held inside a material that is not breathable but has suitable perforations or openings to allow air to flow through it. Alternatively, the object may be the vaporizable substance itself. The object may be formed substantially rod-shaped.

[0047] According to a third aspect of the present invention there is provided an electromagnetically heatable cartridge for use with an electromagnetic induction heating assembly according to the first aspect of the present invention comprising a solid vaporizable substance and an electromagnetically heatable susceptor carried by the vaporizable substance, the electromagnetically heatable susceptor including one or more susceptor plates, where there is more than one susceptor plate, arranged in substantially parallel planes and ring-shaped to provide openings, at least one of which radially surrounds a temperature monitoring region and is located axially between a centre of the cartridge and the temperature monitoring region, and the temperature sensor may protrude into the temperature monitoring region without substantially passing through any of the openings in the susceptor plates when the cartridge is fitted into a heating compartment of the electromagnetic induction heating assembly.

[0048] Preferably, the inductively heatable cartridge according to the third aspect of the present invention may further comprise a deformable portion adjacent to the temperature monitoring area to allow the temperature sensor to protrude into the temperature monitoring area when fitted into the heating compartment of the electromagnetic induction heating assembly, and preferably the deformable portion adjacent to the temperature monitoring area is adapted to deform in use around the temperature sensor when fitted into the heating compartment of the electromagnetic induction heating assembly, thereby allowing the temperature sensor to protrude into the temperature monitoring area. By providing a deformable portion, the surface of the cartridge (which may be, for example, a fibrous paper-like material) remains intact, preventing leakage of the vaporizable material (for example, tobacco material) after the cartridge has been used. Furthermore, this can prevent the temperature sensor from protruding too deep into the cartridge and thus approaching the very strong magnetic field generated at the center of the electromagnetic induction coil of the heating device (which is usually intended to coincide with the center of the cartridge to maximize the heating of the cartridge).

[0049] It should be noted that when using a cartridge with a deformable outer portion rather than a frangible outer portion, a slightly larger opening (relative to when the cartridge has a frangible portion - see below) is typically required in the susceptor adjacent to the temperature monitoring area in order to allow the vaporizable material contained inside the cartridge (preferably solid but deformable tobacco material - e.g. tobacco strands) to be compressed sufficiently to allow the temperature sensor to protrude into the temperature monitoring area. (It should be noted that when a frangible portion is provided, the temperature sensor can be provided with a (sharp) pointed tip that displaces only a small amount of tobacco material when inserted into the cartridge, such that only a relatively small opening is required in the susceptor disk). However, it is preferred that there is a gap between the inner edge of the susceptor and the temperature sensor when inserted into the cartridge, so that the temperature sensor monitors the temperature of the vaporizable material rather than directly monitoring the temperature of the inner edge of the susceptor. Such a gap is preferably between about 5% and 20% of the outer diameter of the cartridge.

[0050] According to a fourth aspect of the present invention there is provided a steam generating apparatus comprising an electromagnetic induction heating assembly according to the first aspect, an electromagnetic induction heatable cartridge according to the second or third aspect arranged inside a heating compartment of the electromagnetic induction heating assembly, an air inlet adapted to supply air to the heating compartment, and an air outlet in communication with the heating compartment.

[0051] The cartridge may be positioned within the heating compartment in any suitable manner. Typically, the cartridge includes a susceptor having an opening in a central region of the cartridge, and the susceptor is oriented and the opening is sized and positioned such that the temperature sensor is located within the opening. This allows the susceptor to couple with the EM field generated during use by the electromagnetic induction coil of the electromagnetic induction heating assembly, while minimizing the EM field that interacts with the temperature sensor of the electromagnetic induction heating assembly and creates noise in the signal generated by the temperature sensor.

[0052] Preferably, the outer portion of the susceptor of the cartridge may be closer to the electromagnetic induction coil of the electromagnetic induction heating assembly than the temperature sensor of the electromagnetic induction heating assembly is to the electromagnetic induction coil, thereby further reducing noise in the signal generated by the temperature sensor by virtue of the susceptor absorbing energy from the EM field instead of the energy being absorbed by the temperature sensor.

[0053] Preferably, the temperature sensor of the electromagnetic induction heating assembly is located between the axial centre of the electromagnetic induction coil of the electromagnetic induction heating assembly and the axial ends of the electromagnetic induction coil, and the part of the electromagnetic induction heatable cartridge is located axially centred of the electromagnetic induction coil during use, which has the same advantages as discussed above in relation to the first aspect. [Brief description of the drawings]

[0054] Exemplary electromagnetic induction heating assemblies and exemplary electromagnetic induction heatable cartridges are described in detail below with reference to the accompanying figures.

[0055] [Figure 1] 1 shows a schematic diagram of an exemplary steam generating device. [Diagram 2] 2 shows an exploded view of the steam generating device according to the embodiment shown in FIG. 1. [Diagram 3] 1 shows a schematic diagram of an exemplary electromagnetic induction coil and temperature sensor. [Figure 4] 1 shows a schematic diagram of an exemplary inductively heatable cartridge, an electromagnetic induction coil, and a temperature sensor. [Figure 5A-5B] 1 illustrates a cross-sectional plan view of an exemplary inductively heatable cartridge. [Figure 6A-6C] 1 shows a schematic diagram of an exemplary susceptor plate. [Figure 7] 1 illustrates an exemplary configuration of an exemplary susceptor plate. [Figure 8] 1 illustrates a further exemplary configuration of an exemplary susceptor plate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0056] An example steam generating device will now be described, including a description of an exemplary electromagnetic induction heating assembly, an exemplary electromagnetic induction heatable cartridge, and an exemplary susceptor.

[0057] 1 and 2, an exemplary steam generating apparatus is generally indicated at 1 in an assembled configuration in FIG. 1 and in an unassembled configuration in FIG.

[0058] The exemplary vapor generating device 1 is a handheld device (which is intended to mean a device that a user can hold and support unassisted in one hand) that includes an electromagnetic induction heating assembly 10, an electromagnetic induction heatable cartridge 20, and a mouthpiece 30. Vapor is emitted by the cartridge when it is heated. Thus, vapor is generated by heating the electromagnetic induction heatable cartridge using the electromagnetic induction heating assembly. The vapor can then be inhaled by a user at the mouthpiece.

[0059] In this example, a user inhales vapour by drawing air from the surrounding environment into the device 1, through or around the inductively heatable cartridge 20 and out the mouthpiece 30 as the cartridge heats up. This is achieved by placing the cartridge in a heating compartment 12 defined by a portion of the electromagnetic induction heating assembly 10, which is in gas communication with an inlet 14 formed in the assembly and an outlet 32 ​​in the mouthpiece when the device is assembled. This allows air to be drawn through the device by applying a negative pressure, which is typically created by the user drawing air through the outlet.

[0060] Cartridge 20 is an object that includes a vaporizable substance 22 and an inductively heatable susceptor 24. In this example, the vaporizable substance includes one or more of tobacco, humectant, glycerin, and propylene glycol. The vaporizable substance may also be a solid (although liquid components such as propylene glycol and glycerin may be absorbed by an absorbent solid material such as tobacco). The susceptor includes multiple electrically conductive plates. In this example, the cartridge also has a layer or membrane 26 to contain the vaporizable substance and the susceptor, which layer or membrane is breathable. In other examples, no membrane is present.

[0061] As described above, an electromagnetic induction heating assembly 10 is used to heat a cartridge 20. The assembly includes an electromagnetic induction heating device in the form of an electromagnetic induction coil 16 and a power source 18. The power source and the electromagnetic induction coil are electrically connected such that power can be selectively transferred between the two components.

[0062] In this example, the electromagnetic induction coil 16 is substantially cylindrical, and as a result, the shape of the electromagnetic induction heating assembly 10 is also substantially cylindrical. The heating compartment 12 is defined radially inside the electromagnetic induction coil, with a bottom at the axial end of the electromagnetic induction coil and a sidewall around the radial inside of the electromagnetic induction coil. The heating compartment is open at the opposite axial end of the electromagnetic induction coil to the bottom. When the steam generating device 1 is assembled, this opening is covered by the mouthpiece 30, and the opening of the exhaust port 32 is located at the opening of the heating compartment. In the example shown in the figures, the intake port 14 has an opening into the heating compartment at the bottom of the heating compartment.

[0063] The temperature sensor 11 is placed at the bottom of the heating compartment 12. The temperature sensor is therefore placed inside the heating compartment at the same axial end of the electromagnetic induction coil 16 as the bottom of the heating compartment. This means that when the cartridge 20 is placed in the heating compartment and when the vapour generating device 1 is assembled (in other words when the vapour generating device is in use or ready for use), the cartridge deforms around the temperature sensor. This is because, in this example, the temperature sensor, thanks to its size and shape, does not pierce the membrane 26 of the cartridge.

[0064] The temperature sensor 11 is also located on the central longitudinal axis 34 of the electromagnetic induction coil 16. As shown in FIG. 3, the electromagnetic induction coil has axial ends 36, 38. These are the terminal ends of the coil. The electromagnetic induction coil also has an axial center 40. This is located halfway between the axial ends of the electromagnetic induction coil. The central longitudinal axis intersects a plane that spans each of the axial ends and the axial center of the electromagnetic induction coil. In FIG. 3, the temperature sensor is shown located only between one axial end and the axial center. This is acceptable in some instances. FIG. 3 also shows exemplary EM field lines 42 of an EM field that can be generated by the electromagnetic induction coil. These are generally elliptical in shape, with the ellipse having its widest point approximately at the axial center of the coil. Due to the location of the temperature sensor relative to the EM field, this results in a weaker interaction with the EM field the further the temperature sensor is located from the axial center.

[0065] FIG. 4 is an enlarged view showing how the electromagnetic induction coil 16, cartridge 20, and temperature sensor 11 are positioned relative to one another when the apparatus is assembled. FIG. 4 also shows exemplary EM field lines 44 of an EM field that can be generated by the electromagnetic induction coil. In this example, there are three susceptor plates, each of which is positioned in a parallel plane, each plane perpendicular to the central longitudinal axis of the electromagnetic induction coil. The susceptor plates are positioned in the center of the cartridge, and therefore their center points are aligned along the central longitudinal axis of the electromagnetic induction coil. The susceptor plates themselves are oriented such that they are perpendicular to the central longitudinal axis of the electromagnetic induction coil.

[0066] The susceptor plates 24 are wider than the temperature sensors 11. This means that portions of each susceptor plate are closer to the electromagnetic induction coil 16 than the temperature sensors. This causes the susceptor plates to interact more with the EM field when it is generated than the temperature sensors do.

[0067] 1 and 2, the temperature sensor 11 is electrically connected to a controller 13 disposed within the electromagnetic induction heating assembly 10. The controller is also electrically connected to the electromagnetic induction coil 16 and a power source 18, and is adapted, during use, to control the operation of the electromagnetic induction coil and the temperature sensor by determining when to provide power from the power source to each of the electromagnetic induction coil and the temperature sensor.

[0068] As mentioned above, to generate vapor, the cartridge 20 is heated. This is accomplished by current supplied by the power supply 18 to the electromagnetic induction coil 16. Current flows through the electromagnetic induction coil, generating a controlled EM field in the area proximate to the coil. The generated EM field provides a source for an external susceptor (in this case the susceptor plate of the cartridge) to absorb and convert EM energy into heat, thereby achieving electromagnetic induction heating.

[0069] More specifically, power is supplied to the electromagnetic induction coil 16, causing a current to pass through the electromagnetic induction coil and generating an EM field. The current supplied to the electromagnetic induction coil is an alternating current (AC) current. This generates heat within the cartridge because, when the cartridge is placed in the heating compartment 12, the susceptor plates are intended to be oriented (substantially) parallel to the radius of the electromagnetic induction coil 16 as shown, or at least have a length component parallel to the radius of the electromagnetic induction coil. Thus, when AC current is supplied to the electromagnetic induction coil while the cartridge is placed in the heating compartment, the orientation of the susceptor plates couples each susceptor plate to the EM field generated by the electromagnetic induction coil, thus inducing eddy currents in each plate. This generates heat in each plate by electromagnetic induction.

[0070] The plates of cartridge 20 are in thermal communication with vaporizable material 22, in this example by direct or indirect contact between each susceptor plate and the vaporizable material. This means that when susceptor 24 is inductively heated by electromagnetic induction coil 16 of electromagnetic induction heating assembly 10, heat is transferred from susceptor 24 to vaporizable material 22, heating vaporizable material 22 and generating vapor.

[0071] When the temperature sensor 11 is in use, it monitors the temperature by measuring the temperature at the surface. Each temperature measurement is transmitted to the controller 13 in the form of an electrical signal.

[0072] The cartridge 20 has several possible configurations. Several exemplary configurations are shown in the remaining figures. Reference is now made to Figures 5A and 5B, which show two exemplary cartridges.

[0073] FIG 5A shows a cartridge 20 having a circular cross section perpendicular to its length. The cartridge has vaporizable material 22 surrounding a circular susceptor plate 24. FIG 5A shows one circular susceptor plate of the cartridge. The center point of the susceptor plate is aligned with the center point of the cartridge. The susceptor plate has a circular opening 46 in its center. This means that in addition to having an outwardly facing edge 48 around the periphery (i.e., outer periphery) of the susceptor plate, the susceptor plate also has an inwardly facing edge 50 around the periphery of the opening.

[0074] In FIG. 5A (and FIG. 5B), a grid 52 is shown. The grid is made up of nine equally sized squares arranged in a 3×3 array. The array is dimensioned such that the outer sides of the array form a tangent to the outer edge of the cartridge 20 shown in FIG. 5A. The sides of the central square of the array (i.e., the central square in the central row and central column) also form a tangent to the perimeter of the opening 46 in the susceptor plate 24. This central region therefore includes the inwardly facing edge 50 of the susceptor plate. The length of the inwardly facing edge in this region is longer than the length of the outwardly facing edge in any of the outer regions provided by the other eight squares of the array. This means that the majority of the heat is generated in the central region when the susceptor plate is coupled to an EM field.

[0075] Figure 5B shows a cartridge 20 similar to that shown in Figure 5A. The only difference is that this cartridge has a pentagonal cross section instead of a circular cross section. In this example, the grid 52 is still the same size and shape as the grid shown in Figure 5A. Thus, the sides of this grid form tangents to a circle (not shown) that connects the vertices of the pentagon.

[0076] Figures 6A, 6B, and 6C show an exemplary configuration of the susceptor plates 24. As mentioned above, the susceptor plates are arranged in three planes. Figures 6A, 6B, and 6C each show one of these planes. Each susceptor plate has two parts 24A, 24B, which are identically shaped segments of a circle. The parts are separated, and the gap between them is in the area where the remainder of the circle of which they are segments would be located, if it existed. Each of the parts has an outwardly facing edge, which is a curved edge that provides an arc from the periphery of the circle. Each part also has an inwardly facing edge. The inwardly facing edge is straight and constitutes the remainder of the periphery of each part.

[0077] Figures 6A-6C show the same grid as Figures 5A and 5B, on which the inwardly facing edges of the portions 24A, 24B of the susceptor plate 24 are spaced apart by the width of one square. In Figure 6A, this means that the inwardly facing edges of these portions are located on opposite sides of the central column of the 3x3 array. The central square of the array thus has the longest length of inwardly facing edges within it, which is longer than the length of the outwardly facing edges in any directly comparable outer region.

[0078] Figures 6B and 6C show a susceptor plate 24 identical to that shown in Figure 6A. The only difference is that the plate has been rotated about its respective center point relative to the orientation of the susceptor plate shown in Figure 6A. The susceptor plate shown in Figure 6B has been rotated approximately 45 degrees (°) clockwise from the orientation of the susceptor plate shown in Figure 6A, and the susceptor plate shown in Figure 6C has been rotated approximately 135° clockwise. Although the grid is not rotated, the central square maintains a longer inwardly facing edge length than any of the other squares, and also maintains a longer inwardly facing edge length than the total length of the outwardly facing edges contained within any square.

[0079] As noted above, Figures 6A-6C show the susceptor plates 24 arranged in parallel planes extending along the central longitudinal axis of the electromagnetic induction coil 11 when the cartridge is assembled. Figure 7 shows a plan view of the susceptor plates in the configuration shown in Figures 6A-6C, separated as in Figures 6A-6C, and arranged as they will be in the cartridge when ready for use. When assembled, the susceptor plates in this arrangement will surround the temperature sensor 11 when the cartridge is placed in the heating compartment. Thus, openings are provided through the susceptor plates to provide susceptors around a complete circle across different levels while maintaining a lateral separation between the susceptor plates and the temperature sensor.

[0080] A further configuration that accomplishes this is shown in Figure 8. Figure 8 shows four sections 24A, 24B, 24C, 24D of a susceptor 24. Like the susceptor plate sections shown in Figures 6A-6C and 7, each section shown in Figure 8 takes the form of a segment of a circle of similar shape, size, and proportions as the susceptor plate sections described above. The susceptor sections shown in Figure 8, when placed in a cartridge, also span three parallel planes. The top and bottom planes have a single section among them, and the middle plane has two sections. The susceptor sections in the planes with two sections within them are positioned and oriented in the same manner as the susceptor section in Figure 6A. The susceptor sections in the other two planes are positioned relative to each other in the same arrangement as the sections in a single plane. The sections are rotated 90° around the center point of the susceptor plate as described above. When assembled, this results in a square opening in the center of the susceptor, and a complete circle around the outside of the susceptor when viewed from above or below. The temperature sensor 11 is also positioned (radially) within the opening.

[0081] The disclosure herein includes at least the following electromagnetic induction heating assembly, electromagnetic induction heatable cartridge, and steam generating device. (Item 1) 1. An electromagnetic induction heating assembly for a steam generating device, comprising: an electromagnetic induction coil defining radially inwardly therefrom a heating compartment for accommodating, in use, an object comprising a vaporizable substance and an electromagnetically inductively heatable susceptor; a temperature sensor disposed opposite a side of the heating compartment on a central longitudinal axis of the electromagnetic induction coil at an end of the heating compartment; An electromagnetic induction heating assembly, wherein the electromagnetic induction coil is adapted to heat the susceptor during use, and the temperature sensor is adapted to monitor a temperature associated with heat generated from the susceptor during use. (Item 2) Item 2. The heating assembly of item 1, wherein the electromagnetic induction coil has a cylindrical shape. (Item 3) 3. The heating assembly according to claim 1 or 2, wherein the temperature sensor is disposed between an axial center of the electromagnetic induction coil and an axial end of the electromagnetic induction coil, preferably the axial end of the electromagnetic induction coil being the axial end closest to the side of the heating compartment opposite which the temperature sensor is disposed. (Item 4) 4. The heating assembly of any one of items 1 to 3, wherein the temperature sensor is sized and positioned such that, during use, it extends no closer to the axial center of the electromagnetic induction coil than a point that is halfway between the axial center of the electromagnetic induction coil and the end of the electromagnetic induction coil proximate the temperature sensor. (Item 5) An electromagnetic induction heatable cartridge for use with the electromagnetic induction heating assembly according to any one of items 1 to 4, a solid vaporizable material; an inductively heatable susceptor carried by the vaporizable material, the inductively heatable susceptor being planar and having an outwardly facing edge and an inwardly facing edge; 1. An electromagnetic induction heatable cartridge, wherein a total length of the inwardly facing edge of the susceptor in a central region of the cartridge having a first area is greater than a total length of the outwardly facing edge of the susceptor in any of a plurality of outer regions of the cartridge, each of the plurality of outer regions having the same shape and orientation as the central region and an area equal to the first area, and the outer regions may extend radially beyond the outer periphery of the cartridge. (Item 6) Item 6. The cartridge of item 5, wherein the susceptor has an opening in the central region. (Item 7) 7. The cartridge of claim 6, wherein the central region has a total length of composite edge that is greater than a total length of composite edge in any of the outer regions, the composite edge including an inwardly facing edge portion and an outwardly facing edge portion. (Item 8) 8. The cartridge according to any one of items 5 to 7, wherein the susceptor includes a plurality of plates, the plates being arranged in parallel planes. (Item 9) 9. The cartridge of claim 8, wherein each plate takes the form of a disk, or a ring, or a portion of a similar shape, each disposed with a radial separation between the plate and a midpoint of the central region. (Item 10) An electromagnetic induction heatable cartridge for use with the electromagnetic induction heating assembly according to any one of items 1 to 4, a solid vaporizable material; an electromagnetically inductively heatable susceptor held by the vaporizable material, the one or more susceptor plates including, if there is more than one susceptor plate, one or more susceptor plates arranged in substantially parallel planes and ring-shaped to provide openings, at least one of the openings radially surrounding a temperature monitoring region and axially disposed between a center of the cartridge and the temperature monitoring region, a temperature sensor may protrude into the temperature monitoring region without substantially passing through the openings of any of the susceptor plates when the cartridge is fitted into the heating compartment of an electromagnetic induction heating assembly, and the cartridge further includes a deformable portion adjacent to the temperature monitoring region for allowing the temperature sensor to protrude into the temperature monitoring region when the cartridge is fitted into the heating compartment of an electromagnetic induction heating assembly. (Item 11) 11. The cartridge according to any one of items 5 to 10, wherein the vaporizable substance comprises tobacco, a humectant, glycerin, and / or propylene glycol. (Item 12) 1. A steam generating device comprising: An electromagnetic induction heating assembly according to any one of items 1 to 4, An electromagnetic induction heatable cartridge according to any one of items 5 to 10, disposed inside a heating compartment of the electromagnetic induction heating assembly; an air inlet adapted to supply air to the heating compartment; and an exhaust outlet in communication with the heated compartment. (Item 13) Item 13. The steam generating apparatus of item 12, wherein the cartridge includes a susceptor having an opening in a central region of the cartridge, the susceptor being oriented and the opening being sized and positioned such that the temperature sensor is disposed within the opening. (Item 14) 14. The steam generating apparatus of claim 12 or 13, wherein an outer portion of the cartridge susceptor is closer to the electromagnetic induction coil of the electromagnetic induction heating assembly than a temperature sensor of the electromagnetic induction heating assembly is to the electromagnetic induction coil. (Item 15) 15. The steam generating device according to any one of items 12 to 14, wherein the temperature sensor of the electromagnetic induction heating assembly is disposed between an axial center of an electromagnetic induction coil of the electromagnetic induction heating assembly and an axial end of the electromagnetic induction coil, and a portion of the electromagnetic induction heatable cartridge is disposed at the axial center of the electromagnetic induction coil during use.

Claims

1. 1. An electromagnetic induction heating assembly for a steam generating device, comprising: an electromagnetic induction coil defining a heating compartment radially inwardly thereof for accommodating, in use, an object comprising a vaporizable substance and a susceptor; a temperature sensor disposed at an end of the heating compartment on a central longitudinal axis of the electromagnetic induction coil; An electromagnetic induction heating assembly, wherein the electromagnetic induction coil is adapted to heat the susceptor during use, and the temperature sensor is adapted to monitor a temperature associated with heat generated from the susceptor during use.

2. The electromagnetic induction heating assembly of claim 1 , wherein the electromagnetic induction coil has a cylindrical shape.

3. The electromagnetic induction heating assembly according to claim 1 or 2, wherein the temperature sensor is located between an axial center of the electromagnetic induction coil and an axial end of the electromagnetic induction coil.

4. 4. The electromagnetic induction heating assembly of claim 3, wherein the temperature sensor is sized and positioned such that, during use, it extends no closer to the axial center of the electromagnetic induction coil than a point halfway between the axial center of the electromagnetic induction coil and the axial end of the electromagnetic induction coil proximate the temperature sensor.

5. 5. The electromagnetic induction heating assembly of claim 4, wherein the axial end of the electromagnetic induction coil is the axial end closest to the end of the heating compartment in which the temperature sensor is located.

6. The electromagnetic induction heating assembly of claim 1 or 2, wherein the temperature sensor is disposed at an axial end of the electromagnetic induction coil.

7. 7. The electromagnetic induction heating assembly of claim 6, wherein the temperature sensor is positioned anywhere from the axial ends of the electromagnetic induction coil up to a distance of one-quarter of the length of the electromagnetic induction coil toward or away from the axial center of the electromagnetic induction coil.

8. The cross-sectional area of ​​the temperature sensor perpendicular to the central longitudinal axis of the electromagnetic induction coil is 10.0 mm ２ 8. The electromagnetic induction heating assembly of claim 1 , wherein the heating resistance is less than 100 Ω / s.

9. 9. The electromagnetic induction heating assembly of claim 1, further comprising a controller disposed within the electromagnetic induction heating assembly and electrically connected to the temperature sensor, the electromagnetic induction coil, and a power source.

10. 1. A steam generating device comprising:

1. An electromagnetic induction heating assembly comprising: an electromagnetic induction coil defining a heating compartment radially inwardly thereof for accommodating, in use, an object comprising a vaporizable substance and a susceptor; a temperature sensor disposed at an end of the heating compartment on a central longitudinal axis of the electromagnetic induction coil; an electromagnetic induction heating assembly, the electromagnetic induction coil adapted to heat the susceptor during use, and the temperature sensor adapted to monitor a temperature associated with heat generated from the susceptor during use; an induction heatable cartridge as the object, the cartridge being at least partially located within the heating compartment of the induction heating assembly; an air inlet configured to supply air to the heating compartment; an exhaust port in communication with the heating compartment; A steam generating device comprising:

11. The steam generating apparatus of claim 10 , wherein an outer portion of the susceptor of the inductively heatable cartridge is closer to the electromagnetic induction coil of the electromagnetic induction heating assembly than the temperature sensor of the electromagnetic induction heating assembly.

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