Characterization of aerosol-generating materials

Abstract

To provide an apparatus and a method for determining a characteristic of an aerosol generating material of an aerosol generating device.SOLUTION: An aerosol generating device comprises a heater for heating an aerosol generating material in use. The apparatus is arranged to: monitor a first property of heating of the aerosol generating material, thereby determining a heating profile of the aerosol generating material; analyze the heating profile to identify a feature of the heating profile corresponding to the heating of one or more constituents of the aerosol generating material; and determine, on the basis of the identified one or more features, the characteristic of the aerosol generating material.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to characterizing aerosol-generating materials, and more particularly to characterizing aerosol-generating materials for aerosol-generating devices. [Background technology]

[0002] Smoking articles, such as cigarettes and cigars, burn tobacco during use, producing tobacco smoke. Attempts have been made to provide alternatives to these smoking articles by producing products that release compounds without combustion. Examples of such products are so-called "heat-not-burn" products, or tobacco heating devices or products, which release compounds by heating a material rather than by burning it. The material may be, for example, tobacco or other non-tobacco products, which may or may not contain nicotine. Summary of the Invention

[0003] According to a first aspect of the present invention, there is provided an apparatus for identifying characteristics of an aerosol-generating material of an aerosol-generating device, the aerosol-generating device comprising a heater for heating the aerosol-generating material during use, the apparatus being configured to monitor a first property of heating of the aerosol-generating material to thereby identify a heating profile of the aerosol-generating material, analyze the heating profile to identify features of the heating profile that correspond to heating of one or more components of the aerosol-generating material, and identify the characteristics of the aerosol-generating material based on the identified feature or features.

[0004] Optionally, the device is configured to analyze the heating profile to identify features of the heating profile that correspond to vaporization of one or more components of the aerosol-forming material.

[0005] Optionally, the first property can be related to the temperature of the aerosol-forming material.

[0006] Optionally, the heater is an induction heater for inductively heating the aerosol-generating material during use, and the device is configured to monitor a first property of the inductive heating of the aerosol-generating material to thereby identify a heating profile of the aerosol-generating material.

[0007] Optionally, the first property comprises a property of an induction heater.

[0008] Optionally, the first property includes a temperature of a susceptor of the induction heater.

[0009] Optionally, the first property comprises an electrical property of the induction heater.

[0010] Optionally, the electrical property comprises a property indicative of a current supplied to an inductor of the induction heater.

[0011] Optionally, the first property includes a frequency characteristic of a resonant drive circuit of the induction heater.

[0012] Optionally, the frequency characteristic includes a resonant frequency of the resonant drive circuit.

[0013] Optionally, the induction heating has a substantially constant induction heating power.

[0014] Optionally, the apparatus is configured to determine a rate of change of the first property, and identify one or more characteristics of the heating profile based on the determined rate of change of the first property.

[0015] Optionally, the one or more characteristics include a portion of the heating profile during which the first property remains substantially constant.

[0016] Optionally, the characteristic includes a temperature of the aerosol-forming material.

[0017] Optionally, the one or more features include a second portion of the heating profile in which the first property changes immediately after a first portion of the heating profile in which the first property remains substantially constant.

[0018] Optionally, the characteristics include an endpoint of vaporization of one or more components of the aerosol-forming material.

[0019] Optionally, the device is configured to control the heater based on the one or more determined characteristics.

[0020] Optionally, the device is configured to determine that an endpoint of vaporization of one or more components of the aerosol-generating material has been reached based on the identified characteristics, and to control the heater in response to determining that an endpoint of vaporization of one or more components of the aerosol-generating material has been reached.

[0021] Optionally, the device is configured to control the heater to further heat the aerosol-forming material by a predetermined amount.

[0022] Optionally, the device is configured to control the delivery of a predetermined amount of energy to the aerosol-forming material.

[0023] Optionally, the device is configured to present information to the user based on the identified characteristics.

[0024] Optionally, the device is configured to present information to the user regarding one or more components of the aerosol-forming material based on the identified properties.

[0025] Optionally, the apparatus is configured to present information to the user about the environment in which the device is operating based on the identified characteristics.

[0026] Optionally, one of the one or more components of the aerosol-forming material is a liquid.

[0027] According to a second aspect of the present invention, there is provided an aerosol generating device comprising an apparatus according to the first aspect and a heater.

[0028] Optionally, the heater is an induction heater, comprising an inductor and a susceptor configured for inductive energy transfer using the inductor, the susceptor configured to heat aerosol-generating material received within the aerosol-generating device during use.

[0029] Optionally, the aerosol-generating device comprises an aerosol-generating material.

[0030] Optionally, the heater has a mass less than the mass of the aerosol-forming material.

[0031] According to a third aspect of the present invention, there is provided a method for identifying characteristics of an aerosol-generating material of an aerosol-generating device, the aerosol-generating device comprising a heater for heating the aerosol-generating material during use, the method comprising the steps of monitoring a first property of heating of the aerosol-generating material to thereby identify a heating profile of the aerosol-generating material, analysing the heating profile to identify features of the heating profile corresponding to heating of one or more components of the aerosol-generating material, and identifying characteristics of the aerosol-generating material based on the identified feature or features.

[0032] According to a fourth aspect of the present invention there is provided a program which, when executed on a processor, causes the processor to carry out a method according to the third aspect.

[0033] Further features and advantages will become apparent from the following description, given by way of example only, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0034] [Figure 1] 1 illustrates a schematic diagram of an aerosol generating device according to an example. [Figure 2] 1 illustrates a schematic diagram of an induction heater according to an example. [Figure 3] 1 shows an example heating profile. [Figure 4]10A and 10B illustrate plots of rate of change of induction heating properties according to an example. [Figure 5] 1 shows a schematic flow diagram of a method according to an example. DETAILED DESCRIPTION OF THE INVENTION

[0035] Induction heating is a process of heating a conductive object (or susceptor) by electromagnetic induction. An induction heater can include an inductive element, such as an electromagnet, and circuitry for passing a varying current, such as an alternating current, through the electromagnet. The varying current in the electromagnet generates a varying magnetic field. The varying magnetic field penetrates a susceptor appropriately positioned relative to the electromagnet and generates eddy currents within the susceptor. The susceptor has an electrical resistance to the eddy currents, so the flow of eddy currents against this resistance causes the susceptor to heat by Joule heating. If the susceptor comprises a ferromagnetic material, such as iron, nickel, or cobalt, heat can also be generated by magnetic hysteresis losses in the susceptor, i.e., by the varying orientation of magnetic dipoles in the magnetic material as a result of aligning the magnetic material with the varying magnetic field.

[0036] In induction heating, heat is generated inside the susceptor, allowing for rapid heating, as compared to, for example, heating by conduction, and further, there is no need for physical contact between the induction heater and the susceptor, allowing for greater flexibility in design and application.

[0037] An induction heater can include an RLC circuit including a resistance (R) provided by a resistor, an inductance (L) provided in part by an electromagnet that can be configured to inductively heat an inductive element, e.g., a susceptor, and a capacitance (C) provided by a capacitor, connected in series. In some cases, the resistance is provided by an ohmic resistance in a portion of the circuit connecting the inductor and capacitor, and thus the RLC circuit does not necessarily include a resistor itself. Such a circuit can be referred to as an LC circuit, for example. RLC and LC circuits can exhibit electrical resonance, which occurs at a specific resonant frequency when the imaginary parts of the impedances or admittances of the circuit elements cancel each other. Resonance occurs in an RLC or LC circuit because the collapsing magnetic field of the inductor generates a current in the winding that charges the capacitor, while the discharging capacitor provides a current that builds up a magnetic field in the inductor. In these circuits described above, when the circuit is driven at the resonant frequency, the series impedance of the inductor and capacitor is minimized and the circuit current is maximized. Therefore, driving an RLC or LC circuit at or near the resonant frequency can provide effective and / or efficient induction heating.

[0038] FIG. 1 schematically illustrates an example aerosol-generating device 100. The aerosol-generating device 100 is portable. The aerosol-generating device 100 includes a battery portion 106, an aerosol-generating portion 104, and a mouthpiece portion 102. The aerosol-generating portion 104 includes a controller 112, an induction heater 114, and an aerosol-generating material 116. The aerosol-generating material 116 may be removable and / or replaceable in the aerosol-generating device 100, for example, via a cartridge (not shown) removably connected to the aerosol-generating device 100. The battery portion 106 includes a battery 110. The battery 110 is configured to power the induction heater 114. The induction heater 114 is configured to inductively heat the aerosol-generating material 116 during use. The controller 112 is configured to control the inductive heating provided by the induction heater 114. The aerosol-generating device 100 is configured to heat an aerosol-generating material 116 to generate an aerosol for inhalation by a user through the mouthpiece portion 102 .

[0039] The aerosol-forming material 116 can include a material that, upon heating, provides a volatilized component, typically in the form of a vapor or aerosol. The aerosol-forming material 116 can be a non-tobacco-containing material or a tobacco-containing material. The aerosol-forming material can include, for example, one or more of tobacco itself, tobacco derivatives, expanded tobacco, reconstituted tobacco, tobacco extract, homogenized tobacco, or tobacco substitutes. The aerosol-forming material can take the form of ground tobacco, cut rag tobacco, extruded tobacco, reconstituted tobacco, reconstituted material, liquid, gel, gelled sheet, powder, or mass. The aerosol-forming material can also include other non-tobacco products, which may or may not contain nicotine, depending on the product. The aerosol-forming material can include one or more humectants, such as glycerol or propylene glycol. In some examples, the aerosol-forming material 116 can include two or more distinct components. For example, the aerosol-forming material 116 can have a first component having a first phase and a second component having a second phase. For example, the aerosol-forming material 116 may include components in solid and liquid forms (at ambient temperature and pressure). For example, the aerosol-forming material 116 may include a tobacco-containing material including, for example, tobacco in solid form and one or more components in liquid form, such as water and / or a humectant. The operating temperature of the aerosol-generating device (i.e., the temperature to which the aerosol-generating material 116 is heated during use to generate an aerosol) may be greater than the vaporization or boiling temperature of one of the one or more components of the aerosol-generating material 116, e.g., greater than the vaporization or boiling temperature of a liquid component of the aerosol-generating material 116, e.g., greater than the boiling temperature of water. The liquid content, e.g., water content, of the aerosol-generating material 116 may vary between batches, between uses, and / or between types of aerosol-generating material 116, and / or may depend on the external environment in which the aerosol-generating material 116 resides.

[0040] In use, a user can activate controller 112, for example, via a button (not shown) or puff detector (not shown), known per se, causing induction heater 114 to heat aerosol-forming material 116, thereby causing aerosol-forming material 116 to generate an aerosol. The aerosol is generated in air drawn into the device through an air inlet (not shown) and carried to mouthpiece 102, where it exits device 100.

[0041] Induction heater 114 and / or device 100 as a whole can be configured to heat aerosol-forming material 116 to a range of temperatures to volatilize at least one component of the aerosol-forming material without burning the aerosol-forming material. For example, the temperature range can be from about 50°C to about 350°C, e.g., from about 50°C to about 250°C, or from about 50°C to about 150°C. In some examples, the temperature range is from about 170°C to about 220°C. In some examples, the temperature range can be outside of this range, and the upper limit of the temperature range can be greater than 350°C.

[0042] Referring now to FIG. 2 , an example of an induction heater 114 that can be used in the aerosol-generating device 100 is shown. The induction heater 114 includes an RLC resonant circuit 200 for inductive heating of a susceptor 210. The resonant circuit 200 includes a resistor 204, a capacitor 206, and an inductor 208 connected in series. The resonant circuit 200 has a resistance R, an inductance L, and a capacitance C. The inductor 208 is configured for inductive energy transfer to the susceptor 210. The susceptor 210 is configured to heat the aerosol-generating material 116. In some examples, the susceptor 210 can be provided with the aerosol-generating material 116, and the susceptor 210 and the aerosol-generating material 116 can be provided in a cartridge (not shown) that is removably connected to the entire device 100, for example, to enable replacement of the cartridge (not shown).

[0043] The inductance L of the circuit 200 is provided by an inductor 208 configured for inductive heating of the susceptor 210. The inductive heating of the susceptor 210 is via an alternating magnetic field generated by the inductor 208, which induces Joule heating and / or magnetic hysteresis losses in the susceptor 210, as described above. A portion of the inductance L of the circuit 200 may be due to the magnetic permeability of the susceptor 210. The alternating magnetic field generated by the inductor 208 is generated by an alternating current flowing through the inductor 208. The alternating current flowing through the inductor 208 is the alternating current flowing through the RLC resonant circuit 200. The inductor 208 may take the form of, for example, a coiled wire.

[0044] The capacitance C of circuit 200 is provided by capacitor 206. The resistance R of circuit 200 can be provided by resistor 204, the resistance of the wires connecting the components of resonant circuit 200, the resistance of inductor 208, and / or the resistance to current flowing in resonant circuit 200 provided by susceptor 210 configured for inductive energy transfer with inductor 108. It will be understood that circuit 200 need not necessarily include resistor 204, and that the resistance R in circuit 200 may be provided by the resistance of the connecting wires, inductor 208, and / or susceptor 210.

[0045] The alternating current is driven in circuit 200 by suitable drive circuitry 202, such as an H-bridge driver 202 or another variable or alternating current source. The drive circuitry 202 is controllable by controller 112 to provide the alternating current in resonant circuit 200. The drive circuitry 202 is connected to a DC voltage source from battery 110. For example, drive circuitry 202 can provide the alternating current in circuit 100 from the DC voltage source of battery 110 by inverting (and then restoring) the voltage across the circuit via switching components (not shown). This can be useful because it allows the RLC resonant circuit to be powered by a DC battery and allows the frequency of the alternating current to be controlled.

[0046] The drive circuitry 202 is connected to the controller 112. The controller 112 controls the drive circuitry 202 or its components (not shown) to provide an alternating current I in the RLC resonant circuit 200 at a given drive frequency f. The drive frequency f may be, for example, a resonant frequency f of the particular RLC circuit 200. r or approximately at its resonant frequency f r It can be controlled so that

[0047] It may be desirable to determine the properties of the aerosol-generating material 116, such as the properties of the aerosol-generating material 116 during induction heating of the aerosol-generating material 116. For example, it may be useful to determine or calibrate the temperature of the aerosol-generating material 116, thereby enabling precise control of the heating of the aerosol-generating material 116, for example. As another example, it may be useful to determine when water or other components of the aerosol-generating material 116 have vaporized during heating, or when an endpoint of vaporization of a component of the aerosol-generating material 116 has been reached, because this can enable improved control of further heating of the aerosol-generating material to the vaporization temperature of one or more other components. For example, the aerosol-generating material 116 may contain a variable water content, which may vary significantly depending on many factors, such as the manufacturing process, the external environment, etc. Determining when substantially all of the water has evaporated from the aerosol-generating material 116 during heating can allow for control of further heating of the aerosol-generating material independent of the initial water content, thereby enabling, for example, more consistent aerosol delivery and more efficient heating control. For example, the point at which water has completed vaporization can infer a certain amount of additional energy that will then be required to reach the vaporization temperature of the other components.

[0048] According to an example embodiment of the present invention, an apparatus (e.g., a controller 112) is configured to identify a characteristic of the aerosol-generating material 116 during heating of the aerosol-generating material 116. In overview, as described in more detail below, the controller 112 is configured to monitor a first property P of the inductive heating of the aerosol-generating material 116 to thereby identify a heating profile of the aerosol-generating material 116. The controller 112 is configured to analyze the heating profile to identify a characteristic of the heating profile that corresponds to heating (e.g., vaporization) of one or more components of the aerosol-generating material 116. The controller 112 is configured to identify a characteristic of the aerosol-generating material based on the identified characteristic or characteristics. For example, the characteristic may be the temperature of the aerosol-generating material 116 and / or the endpoint of vaporization of a component (e.g., water) of the aerosol-generating material 116. As described in more detail below, identifying such a characteristic may enable, for example, accurate identification of the temperature of the aerosol-generating material and / or improved control of further heating of the aerosol-generating material 116.

[0049] As described above, the controller 112 is configured to monitor a first property P of the inductive heating of the aerosol-forming material 116 to thereby identify a heating profile of the aerosol-forming material 116 .

[0050] 3, an exemplary heating profile 302 of the aerosol-generating material 116 is shown schematically. The heating profile 302 corresponds to the value of a first property P of the inductive heating of the aerosol-generating material 116 as a function of time t. As the inductive heater 114 heats the aerosol-generating material 116, the first property P of the inductive heating changes as a function of time t. The first property P can be recorded by the controller 121 as a function of time t, for example, in a storage or memory (not shown), either continuously or discretely.

[0051] In some examples, the first property P can be related to the temperature of the aerosol-generating material 116. For example, the property P can be the measured temperature of the aerosol-generating material 116. For example, the temperature of the aerosol-generating material 116 can be sensed by a separate temperature sensor (not shown) positioned at or near the aerosol-generating material 116. The controller 112 can be communicatively coupled to the temperature sensor (not shown) and can collect temperature data from the temperature sensor (not shown) to monitor the temperature of the aerosol-generating material 116 as a function of time t.

[0052] In some examples, the first property P is a property of the induction heater 114. For example, the first property P may include the temperature of the susceptor 210 of the induction heater 114. For example, a temperature sensor (not shown) may be disposed at or near the susceptor 210. In this regard, it should be understood that the temperature of the susceptor 210 may be a function of the heating of the aerosol-generating material 116. The controller 112 may be communicatively coupled to the temperature sensor (not shown) and may collect temperature data from the temperature sensor (not shown) to monitor the temperature of the susceptor 210 as a function of time t. Because the susceptor 210 is configured to heat the aerosol-generating material 116, it may be in thermal contact or in close thermal contact with the aerosol-generating material 116, for example, and the specified temperature of the susceptor may be the same as or similar to the temperature of the aerosol-generating material 116, or at least a portion of the aerosol-generating material 116.

[0053] The first property P need not necessarily be a direct temperature measurement of the susceptor 210 and / or the aerosol-generating material 116 by a separate temperature sensor (not shown). For example, in some instances, the first property P includes an electrical property of the induction heater 114 (or more generally, the circuit 200), which may be indicative of the temperature of the susceptor 210 and / or the aerosol-generating material 116.

[0054] In one example, the first property P includes a property indicative of the current I supplied to the inductor 208 of the induction heater 114. As described above, the battery 110 can supply a DC voltage (and substantially a DC current) to the drive circuitry 202, which in turn supplies an AC current to the resonant circuit 200, including the inductor 208. As the temperature of the susceptor 210 increases due to induction heating, properties of the susceptor 210 (e.g., the ohmic resistance of the susceptor 210) may change. By way of purely example, the ohmic resistance of the susceptor 210 may increase with temperature. In turn, the increase in the ohmic resistance of the susceptor 210 may increase the overall effective resistance R of the resonant circuit 200. Thus, by Ohm's Law, for a given DC supply voltage, e.g., provided by battery 110, as the effective resistance R of resonant circuit 200 increases, the current I drawn from battery 110 by drive circuitry 202 decreases, causing a decrease in current I flowing through resonant circuit 200 and therefore a decrease in current I supplied to inductor 208. Thus, the current I supplied to inductor 208 of induction heater 114 can be related to the relative temperature of susceptor 210 and used as a first property P of the inductive heating of aerosol-generating material 116.

[0055] The current I drawn from the battery 110 by the drive circuitry 202, the current I flowing within the resonant circuit 200, and / or the current I supplied to the inductor can be monitored by the controller 112 in several ways. For example, the current I can be measured passively or actively. For example, a current meter (not shown) can be applied to a supply line (not shown) between the battery 110 and the drive circuitry 202 to measure the current drawn by the drive circuitry 202. This measurement can be provided to the controller 112, which can monitor the current I as a first property P as a function of time t. As another example, a pickup coil (not shown) can be placed in proximity to the inductor 208, and a voltage meter (not shown) can be used to measure the voltage induced across the pickup coil (not shown) by the inductor 208. The induced voltage can be proportional to the current I flowing within the resonant circuit 200 and supplied to the inductor 208. Thus, the induced voltage is an example of a property indicative of the current I supplied to the inductor 208 of the induction heater 114. The measured induced voltage may be provided to the controller 112, which may monitor the induced voltage and / or convert the induced voltage into a measure of the current I flowing in the resonant circuit 220 as a first property P.

[0056] It should be understood that in other embodiments, an electrical property of circuit 200 other than current I can be measured as first property P.

[0057] In some examples, the first property P includes a frequency characteristic of the resonant circuit 200 of the induction heater 114 .

[0058] For example, the frequency characteristic is the resonant frequency f r The resonant frequency f of the circuit 200 can be r may depend on the capacitance C and inductance L of the circuit 200 and may be given by:

[0059]

number

[0060] The inductance L of the inductor 208, and therefore of the resonant circuit 200, depends on the magnetic permeability μ of the susceptor 210. The magnetic permeability μ is a measure of a material's ability to support the formation of a magnetic field within itself and represents the degree of magnetization the material acquires in response to an applied magnetic field. The greater the magnetic permeability μ of the susceptor 210, the greater the inductance L. The magnetic permeability μ of the material from which the susceptor 116 is constructed can change with temperature. For example, the Curie temperature T c For susceptors including ferromagnetic and ferrimagnetic materials operating below 100°C, for example, as the temperature of the susceptor 210 increases, the magnetic permeability μ of the susceptor 210 decreases, which in turn decreases the inductance L in the resonant circuit 200, which in turn decreases the resonant frequency f of the resonant circuit 200, according to equation (1). r Therefore, the resonant frequency f of the resonant circuit 200 of the induction heater 114 decreases. r can be related to the relative temperature of the susceptor 210 and can be used as a first property P of the inductive heating of the aerosol-generating material 116.

[0061] The resonant frequency f of the resonant circuit 200 r The resonant frequency f can be measured using any suitable means. r At this frequency, the series impedance Z of the inductor 208 and the capacitor 206 is at a minimum, and therefore the current I is at a maximum. rcan be determined by controller 112 configured to measure the frequency response of resonant circuit 200. For example, controller 112 can be configured to intermittently measure the current I flowing in RLC circuit 100 (or a parameter that can be related to the current I flowing in RLC circuit 200, as described above) as a function of the drive frequency at which the RLC circuit is driven. For example, controller 112 can be configured to control drive circuitry 202 to scan across a range of drive frequencies f. The current I flowing in circuit 200 (or a parameter that can be related thereto) can be measured during the drive frequency scan, thereby determining the frequency response of RLC circuit 200 as a function of drive frequency f. From the frequency response, the resonant frequency f r can be identified as the frequency f at which the current I flows through the circuit 200 is at a maximum, for example. This process is repeated over time to obtain the variation of the frequency f (as the first property P) as a function of time t.

[0062] Referring again to FIG. 3 , a first property P of the inductive heating of the aerosol-generating material is monitored as a function of time t to determine a heating profile 302 of the aerosol-generating material 116. For ease of explanation, the following description of FIG. 3 assumes that the first property P is directly proportional to the temperature of the aerosol-generating material; however, as explained above, it will be understood that in other examples, any first property P of the inductive heating of the aerosol-generating material can be used. Furthermore, for ease of explanation, the following description of FIG. 3 assumes that the inductive heating power (i.e., the rate of energy delivered to the aerosol-generating material by inductive heating) remains substantially constant over the heating profile 320; however, it will be understood that this is not necessarily the case, and in other examples (not shown), the inductive heating power may vary, as will be explained in more detail below.

[0063] In the example shown in FIG. 3 , at time t0, the first property P is at some initial value P0, which corresponds to some initial temperature of the aerosol-generating material 116. When induction heating begins (using a constant heating power in this example), the first property P increases as a function of time t from t0 to t1. This corresponds to an increase in the temperature of the aerosol-generating material 116 because the energy applied to the aerosol-generating material 116 by the susceptor 210 increases the temperature of the aerosol-generating material 116. However, at time t1, the first property P substantially stops increasing (which may include increasing at a different or substantially reduced rate) and instead remains substantially constant at a value P1 from time t2 to t3. In other words, from time t1 to t2, there is a portion 304 where the first property P remains substantially constant (stagnation) as a function of time t.

[0064] The first property P remains constant between times t1 and t2 due to the latent heat of vaporization of the components of the aerosol-generating material. This latent heat is the energy supplied to the components of the aerosol-generating material 116 at their boiling points to change their phase (e.g., from liquid to gas) without changing the temperature of the aerosol-generating material 116. In other words, the first property P remains substantially constant because, although the aerosol-generating material 116 remains inductively heated (in this example, at a constant heating power), the energy supplied to the aerosol-generating material 116 is being used to vaporize the components of the aerosol-generating material 116 rather than increasing the temperature of the aerosol-generating material 116. As an example, the component can be water, which has a known boiling point of 100°C. Therefore, between times t and t2, when the first property P remains substantially constant at P1, it can be accurately determined that the temperature of the aerosol-generating material 116 is 100°C, i.e., the value P1 of the first property P corresponds to a temperature of the aerosol-generating material 116 of 100°C.

[0065] At time t2, the first property P begins to increase again, corresponding to an increase in the temperature of the aerosol-generating material 116. The first property P increases at t2 due to the vaporization of all or substantially all of the components of the aerosol-generating material 116, and thus, inductive heating of the aerosol-generating material 116 again increases the temperature of the aerosol-generating material 116. Portion 306 of the heating profile 302, immediately following portion 304 where the first property P remains substantially constant, where the first property P begins to increase again, may correspond to, for example, the endpoint of the vaporization of a component of the aerosol-generating material. For example, the component may be water, and at t2, it may be accurately determined that all or substantially all of the water in the aerosol-generating material 116 has vaporized, and that, for example, the water content of the aerosol-generating material at time t2 is substantially zero.

[0066] As described above, the device (e.g., controller 112) is configured to analyze the heating profile 302 to identify features of the heating profile 302 that correspond to the vaporization of one or more components of the aerosol-generating material 116. The device (e.g., controller 112) is configured to determine a characteristic of the aerosol-generating material 116 based on the identified feature or features. For example, the controller 112 may include a processor (not shown) and a memory (not shown). The processor may, for example, extract the heating profile data stored in the memory and process the data to perform the analysis and / or characterization of the heating profile. It should be understood that the heating profile data may include at least two data points representing a first property P at two different times, which may then be used to calculate a change in the first property P.

[0067] In some examples, the characteristics of the heating profile 302 include a portion 304 of the heating profile 302 in which the first property P is substantially constant. The controller 112 can determine the temperature of the aerosol-generating material based on identifying the characteristics of the first property P that remain substantially constant. For example, as described above, the component can be water, which has a known boiling point of 100°C. Thus, upon identifying the characteristics of the first property P that remain substantially constant, the controller 112 can determine that the temperature of the aerosol-generating material 116 is approximately 100°C.

[0068] In some examples, the mass of the heater 114, e.g., the mass of the susceptor 210 of the induction heater 114, can be greater than the mass of the aerosol-generating material 116. This can help ensure that the first property P can be accurately related to the temperature of the aerosol-generating material. For example, this can help ensure that the feature of the first property P that remains substantially constant is easily identifiable, which can help improve the reliability and / or accuracy of identifying the heating profile feature and therefore the properties of the aerosol-generating material 116. Furthermore, the induction heating power supplied can be such that the heating profile feature is easily identifiable. For example, if the feature is the portion 304 where the first property P remains substantially constant, the induction heating power supplied can be such that the time between times t1 and t2 is sufficiently large to make the portion 304 easily identifiable. As will be appreciated, the induction heating power that results in the heating profile feature being easily identifiable can depend on the mass and / or type of the aerosol-generating material used and / or the mass and / or type of the susceptor used to heat the aerosol-generating material.

[0069] The aerosol-generating material 116 may include other known vaporizable components. For example, the aerosol-generating material 116 may be known to include multiple, e.g., two, known vaporizable components. For example, a first of the components may be known to have a boiling point of X°C, and a second of the components may be known to have a boiling point of Y°C, where X°C is lower than Y°C. Thus, for example, upon heating the aerosol-generating material, the controller 112 may determine that the temperature of the aerosol-generating material is X°C when a first portion (not shown) of the heating profile is reached in which the first property P remains substantially constant, and may determine that the temperature of the aerosol-generating material is Y°C when a second portion (not shown) of the heating profile is reached in which the first property P remains substantially constant. Thus, the controller 112 may reliably and accurately determine the temperature of the aerosol-generating material 116. This may result in a more reliable temperature determination compared to, for example, direct temperature measurement using a temperature sensor because, for example, this method may be less susceptible to calibration errors.

[0070] As another example, the one or more characteristics may include a first portion 304 of the heating profile 302 in which the first property P remains substantially constant, followed immediately by a second portion 306 of the heating profile 302 in which the first property P changes. The controller 112 can identify the endpoint of vaporization of one or more components of the aerosol-generating material 116 based on the identification of such characteristics. For example, as described above, the component may be water. When the first property P begins to increase again immediately after the portion in which the first property P remains substantially constant, it can be accurately determined that the endpoint of water vaporization has been reached, i.e., that all or substantially all of the water in the aerosol-generating material 116 has vaporized. Thus, for example, it can be determined that the water content of the aerosol-generating material 112 at this point is substantially zero. As described in more detail below, this can enable improved control of further heating of the aerosol-generating material 116.

[0071] In some examples, the controller 112 can be configured to control the induction heater 114 based on one or more identified characteristics. For example, the controller 112 can control the induction heater 114 to increase or decrease the induction heating power, and / or apply a different heating power, and / or control the induction heater 114 to stop providing induction heating, and / or control the induction heater 114 to provide induction heating according to a predetermined control pattern or sequence, and / or provide a predetermined additional induction heating and / or a predetermined additional amount of energy to the aerosol-forming material 116. The controller 112 can control the induction heater 114, for example, by controlling the current supplied to the drive means 202 or by controlling the drive frequency f of the drive circuitry 202.

[0072] As explained above, the determined characteristic can be the temperature of the aerosol-generating material 116. The controller 112 can control the induction heater 114 based on the determined temperature of the aerosol-generating material. For example, upon determining that a given temperature (e.g., corresponding to the boiling point of a known component) has been reached, the controller 112 can control the induction heater 114 according to a predetermined control sequence or a specific heating profile. This can help, for example, to prevent overheating of the aerosol-generating material.

[0073] As discussed above, as another example, the identified characteristic may be an endpoint of vaporization of a component of the aerosol-generating material. The controller 112 may be configured to determine that an endpoint of vaporization of one or more components of the aerosol-generating material has been reached and to control the induction heater in response to determining that the endpoint of vaporization of one or more components of the aerosol-generating material has been reached. For example, the controller 112 may control the induction heater 114 to further inductively heat the aerosol-generating material 116 by a predetermined amount. For example, the controller 112 may control the delivery of a predetermined amount of energy to the aerosol-generating material 116.

[0074] For example, different aerosol-generating materials 116 that can be used with the aerosol-generating device 100, or different batches of the same aerosol-generating material 116 that can be used (e.g., serially) with the aerosol-generating device 100, can contain varying water contents (or varying contents of other components). Identifying the point during heating at which all of the water (or other components) has evaporated from the aerosol-generating material 116 allows for control of further heating of the aerosol-generating material independent of the initial water (or other component) content, thereby enabling more consistent aerosol delivery and more efficient heating control. In other words, water-related fluctuations are eliminated (or substantially reduced), allowing the controller 112 to supply a set amount of power to the susceptor 210 / aerosol-generating material 116 from the point at which the water has substantially evaporated. This means that the operating temperature can be reached with greater precision.

[0075] For example, the additional energy required to raise the temperature of the aerosol-generating material 116 to a given operating temperature (e.g., the optimal temperature at which the aerosol-generating material 116 generated an aerosol) after water (or other components) has vaporized can be pre-specified, and the controller 112 can control the induction heater 114 to supply that pre-specified amount of energy to the aerosol-generating material 116. This can enable simpler and / or more accurate control of the induction heating. For example, the control can be independent of the initial component (e.g., water) content of the aerosol-generating material, which can vary between uses, batches, or types of the aerosol-generating material. For example, this can enable at least a portion of the induction heating control to be applied more accurately, e.g., compared to a control that does not take these variations into account, and / or more simply, e.g., compared to a control that takes these variations into account across the entire control range. Thus, the controller 112 can enable improved control of the inductive heating of the aerosol-generating material and an improved aerosol-generating device 100.

[0076] In another example, the controller 112 can be configured to present information to a user based on the determined characteristics of the aerosol-generating material 116. For example, if the determined characteristics indicate that all water (or other components) have evaporated from the aerosol-generating material 116, information indicating this can be provided to the user. In another example, the information presented to the user can indicate the temperature of the aerosol-generating material 116. For example, if the determined characteristics indicate that all water has evaporated from the aerosol-generating material 116, the information can inform the user that the aerosol-generating material 116 is at the boiling temperature of water. In another example, the user can be presented with information regarding the composition of the aerosol-generating material 116. For example, information regarding the composition of the aerosol-generating material 116 can be determined based on analysis of the heating profile 302. For example, as discussed above, analysis of the heating profile can reveal the presence of a first vaporizable component and a second vaporizable component having different boiling points in the aerosol-generating material 116. Accordingly, the user can be presented with information indicating the presence of these components in the aerosol-generating material 116. Controller 112 may further, in some examples, determine whether aerosol-generating material 116 is approved for use with device 100 based on the determined information regarding the composition of aerosol-generating material 116. In examples, controller 112 may present such information to a user, and / or controller 112 may be configured to take actions such as determining whether to enable operation of device 100 to heat the aerosol-generating material based on whether the aerosol-generating material 116 is approved for use with device 100. In another example, controller 112 may be configured to determine parameters related to the environment in which device 100 is operating based on the determined characteristics of aerosol-generating material 116. For example, controller 112 may determine the amount of water in aerosol-generating material 116 based on characteristics of heating profile 302.In an example, the amount of water in aerosol-generating material 116 can indicate the humidity of the environment in which device 100 is operating. Thus, a user can be presented with information regarding, for example, the humidity of the environment.

[0077] In some examples, the controller 112 is configured to determine the rate of change of the first property P, for example, the rate of change of the first property as a function of time. The controller 112 can be configured to identify one or more characteristics of the heating profile based on the determined rate of change of the first property. FIG. 4 schematically illustrates a plot 402 of the rate of change dP / dt of the first property P as a function of time t. As in FIG. 3, FIG. 4 assumes that the induction heating has a constant heating power and that the property P is directly proportional to the temperature of the aerosol-generating material 116. At time t0, induction heating begins, and the rate of change dP / dt (i.e., in this example, the first derivative of the first property P with respect to time t) is at a value Q1. This remains true until time t1, at which time the rate of change dP / dt reduces to substantially zero and remains there until t2. This indicates that in a portion 404 of the plot 402 over the time range t1-t2, the property P does not change substantially, i.e., remains substantially constant as a function of time t. As explained above, it can be determined from this that, for example, a component (e.g., water) has reached its boiling point (or vaporization point) and therefore the temperature of the aerosol-generating material 116 at this point is the boiling point (or vaporization point) of the component, e.g., 100°C for water. At time t2, in the second portion of plot 402, the rate of change dP / dt increases again. This indicates that the property P begins to increase again (immediately after portion 404, where property P remained substantially constant), and thus the controller 112 can determine from this that the endpoint of vaporization of the component (e.g., water) of the aerosol-generating material 116 has been reached, as explained above. The controller 112 can then control the induction heater 114 based on this determination, as explained above. Identifying one or more features of the heating profile based on the identified rate of change of the first property P can enable the controller 112 to sensitively identify relevant changes in the first property P, thereby enabling reliable and accurate control.

[0078] 5 schematically illustrates a method for characterizing the aerosol-generating material 116 of the aerosol-generating device 100. As described above, the aerosol-generating device 100 includes an induction heater 114 for inductive heating of the aerosol-generating material 116 during use. The method can be performed, for example, by an apparatus, such as the controller 112 of the aerosol-generating device 100. The controller 112 (or other apparatus) can include a processor (not shown) and a memory (not shown). The memory (not shown) can store instructions (e.g., a computer program) that, when executed by the processor (not shown), cause the controller 112 (or other apparatus) to perform the method.

[0079] In step 502, the method includes monitoring a first property P of the inductive heating of the aerosol-generating material 116 to thereby determine a heating profile of the aerosol-generating material 116. In some examples, the first property P can be any of the first properties P described above. The heating profile can be, for example, similar to that described above with reference to FIG. 3.

[0080] In step 504, the method includes analyzing the heating profile to identify features of the heating profile that correspond to vaporization of one or more components of the aerosol-generating material. As described above, the features can include portions where the first property P remains substantially constant (e.g., indicative of vaporization of a component) and / or portions where the first property P changes immediately after the portion where the first property remains substantially constant (e.g., indicative of an endpoint of vaporization of a component).

[0081] In step 506, the method includes determining a property of the aerosol-generating material based on the identified one or more characteristics. As described above, the property can be, for example, the temperature of the aerosol-generating material 116 and / or the vaporization endpoint of a component of the aerosol-generating material 116. Although not shown in FIG. 5, the method can include controlling the induction heating based on the determined property, for example, as described above.

[0082] In some examples, monitoring the first property P of the induction heating to determine a heating profile and analyzing the heating profile to identify features corresponding to the vaporization of one or more components of the aerosol-generating material 116 may occur substantially continuously or substantially contemporaneously (i.e., simultaneously). For example, analysis of the heating profile may occur as the first property is being monitored, i.e., in real time. For example, analysis may be performed on the current value of the first property and one or more values ​​of the first property P determined or recorded immediately before the current value of the first property P. Performing the monitoring and analysis substantially contemporaneously may enable more responsive determination of the properties of the aerosol-generating material 116 and, therefore, more accurate and reliable control of the aerosol-generating device 100.

[0083] In some of the above examples, it has been assumed that the first property P is directly proportional to the temperature of the aerosol-forming material. However, it will be appreciated that this is not necessarily the case, and in other examples, the first property P may have other dependencies on the temperature of the aerosol-forming material, but that the heating profile can nevertheless be analyzed to identify features of the heating profile that correspond to the vaporization of one or more components of the aerosol-forming material.

[0084] In some of the above examples, it has been assumed that induction heating was performed using a constant induction heating power. However, it will be understood that the aerosol-generating material 116 does not necessarily need to be heated using a constant induction heating power to identify the properties, and that in other examples, variable induction heating power may be used. Similarly, it will be understood that the first property P does not necessarily need to be monitored as a direct function of time t to identify a heating profile; i.e., the identified heating profile does not necessarily need to be the first property P as a direct function of t. For example, in other examples, the first property P can be monitored as a function of, for example, energy E supplied to the aerosol-generating material 116 and / or consumed by the induction heater 114. Thus, the heating profile can include the first property P as a function of energy E supplied to the aerosol-generating material 116 and / or energy consumed by the induction heater 114. The energy E can be determined, for example, by multiplying the power (e.g., consumed by the induction heater 114) supplied to (i.e., consumed by) the induction heater 114 (which can be the same as, similar to, or proportional to, the induction heating power supplied by the induction heater 104) by the time t for which the power is supplied. As in the above example, when the components of the aerosol-generating material 116 begin to vaporize, the first property P may remain substantially constant as a function of the supplied energy E. This is because the energy E is used to vaporize the components of the aerosol-generating material instead of increasing the temperature of the aerosol-generating material. Thus, for example, at this point, the temperature of the aerosol-generating material 116 can be accurately identified as the boiling point (or vaporization point) of the components. Similarly, when the first property P increases immediately after the portion where the first property remained substantially constant, it can be determined that the endpoint of the vaporization of the components has been reached. As described above, further heating by the induction heater 114 can then be controlled based on the achievement of this point.

[0085] In some of the above examples, the apparatus for identifying the properties of the aerosol-generating material 116 is described as being the controller 112 of the aerosol-generating device 100. However, it will be appreciated that this need not necessarily be the case, and that in other examples the apparatus may not be an internal or integral component of the aerosol-generating device 100, but may, for example, be provided as a separate apparatus.

[0086] In a further example, the characteristic of the first property P can be used to identify the aerosol-generating material 116 and / or determine whether the aerosol-generating material 116 is intended for use with the aerosol-generating device 100. For example, the controller can determine that the aerosol-generating material 116 is not intended for use with the aerosol-generating device 100. This can be based on explicitly identifying the aerosol-generating material (e.g., by name or composition) or on comparing the characteristic of the first property P to an expected characteristic (e.g., pre-stored). If the measured characteristic of the first property P differs from the expected characteristic, the controller can prevent heating of the aerosol-generating material 116 or provide a warning to the user of the device 100.

[0087] In some of the above examples, the aerosol-generating device is described as including an induction heater for inductively heating the aerosol-generating material during use, and the apparatus is configured to monitor a first property of the inductive heating of the aerosol-generating material to identify a heating profile of the aerosol-generating material. However, this need not necessarily be the case, and it will be understood that in some examples, the aerosol-generating device can include any heater for heating the aerosol-generating material during use, and the apparatus can be configured to monitor a first property of the heating of the aerosol-generating material to identify a heating profile of the aerosol-generating material. For example, in some examples, the heater can be a resistive heater, and the first property can be the temperature of the aerosol-generating material, as measured by a temperature sensor, such as those described above by way of example.

[0088] In some of the above examples, the device is described as analyzing the heating profile to identify features of the heating profile that correspond to the vaporization of one or more components of the aerosol-generating material. However, this is not necessarily the case, and it will be understood that in some examples, the device can analyze the heating profile to identify features of the heating profile that correspond (more generally) to the heating of one or more components of the aerosol-generating material. For example, a feature of the heating profile, aside from the vaporization of one or more components of the aerosol-generating material, can be, for example, a certain heating gradient (e.g., the rate at which one or more components of the aerosol-generating material are heating). The identified heating gradient can then be used, for example, to identify a characteristic of the aerosol-generating material. For example, different components of the aerosol-generating material can have different heat capacities, which may affect the identified heating gradient. Thus, the characteristic of the aerosol-generating material can be the identity of the components of the aerosol-generating material and / or, for example, the type of aerosol-generating material. As another example, different amounts of a certain aerosol-generating material (or its components) can result in different observed heating gradients. Thus, the property of the aerosol-generating material can be the (current) amount of the aerosol-generating material (or a component thereof). It will be appreciated that other features of the heating profile corresponding to the heating of one or more components of the aerosol-generating material can be identified and used to characterize the aerosol-generating material.

[0089] In another example, the device can analyze the heating profile to identify features of the heating profile that correspond to the vaporization of one or more components of the aerosol-generating material using slopes associated with different portions of the heating profile. For example, before a component, such as water, is vaporized from the aerosol-generating material, the heating profile can have a first slope M1. However, after all the water in the aerosol-generating material is vaporized, the heating profile can have a second slope M2. In this example, the second slope M2 is greater than the first slope M1 because, at the point in the heating profile with slope M2, the water is no longer being heated and the aerosol-generating material 116 requires less energy to increase its temperature by a given amount. To identify an inflection point in the heating profile, a point can be identified where a tangent to the heating profile has slopes M1 and M2. Features of the heating profile that correspond to the vaporization of one or more components of the aerosol-generating material can be identified. This can be useful when the inflection point is not easily identifiable by other techniques, for example, when the induction heating power is so high that the inflection point is short-lived.

[0090] It should be noted that it is the heating profile features of the aerosol-generating material itself that are identified to characterize the aerosol-generating material. Thus, in some examples, the properties of the (induction) heater may be monitored to characterize the heating profile of the aerosol-generating material, but it is nonetheless the heating profile features corresponding to the heating of one or more components of the aerosol-generating material that are identified to characterize the aerosol-generating material. This may be in contrast to, for example, some characteristics of the heater (e.g., the susceptor of an induction heater) itself. Identifying the heating profile features corresponding to the heating of one or more components of the aerosol-generating material to characterize the aerosol-generating material can allow properties unique to the aerosol-generating material being heated to be identified, which has advantages such as improved consistency and heating control, as described hereinabove.

[0091] The above examples are to be understood as illustrative examples of the present invention. It will be understood that any feature described in connection with any one example can be used alone or in combination with other features described, in combination with one or more features of any other of the examples, or in any combination with any other of the other examples. Furthermore, equivalents and modifications not described above may also be used without departing from the scope of the present invention, which is defined in the appended claims.

Claims

1. 1. An apparatus for identifying a characteristic of an aerosol-generating material in an aerosol-generating system comprising an aerosol-generating device and an article containing the aerosol-generating material, the apparatus comprising: the characteristics include a temperature of the aerosol-forming material and / or an end point of vaporization of a component of the aerosol-forming material; the aerosol generating system includes a heater for heating the aerosol-forming material during use; The device comprises: monitoring a first property of the heating of the aerosol-forming material to identify a heating profile of the aerosol-forming material; Identifying one or more characteristics of the heating profile; determining the property of the aerosol-forming material based on the identified one or more characteristics; The apparatus is configured to determine when all water has evaporated from the aerosol-forming material during heating.

2. 10. The apparatus of claim 1, wherein the apparatus is configured to control heating of the aerosol-forming material based on determining when all of the water has evaporated from the aerosol-forming material during heating.

3. The apparatus of claim 1 , wherein the first property of the heating of the aerosol-forming material is a measured temperature of the aerosol-forming material.

4. The device of claim 3 , wherein the measured temperature of the aerosol-forming material is obtained from a temperature sensor of the device.

5. 2. The apparatus of claim 1, wherein the first property of the heating of the aerosol-forming material is an electrical property of the heater that is indicative of the temperature of the heater.

6. The apparatus of claim 5 , wherein the electrical property of the heater is a current supplied to an inductor of the heater or a frequency characteristic of a resonant circuit of the heater.

7. 1. A method for identifying a property of an aerosol-generating material in an aerosol-generating system including an aerosol-generating device and an article containing the aerosol-generating material, comprising: the characteristics include a temperature of the aerosol-forming material and / or an end point of vaporization of a component of the aerosol-forming material; the aerosol generating system includes a heater for heating the aerosol-forming material during use; The method comprises: monitoring a first property of the heating of the aerosol-forming material to identify a heating profile of the aerosol-forming material; Identifying one or more characteristics of the heating profile; determining the properties of the aerosol-forming material based on the one or more identified characteristics and an endpoint of vaporization of all water within the aerosol-forming material during heating; method.

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