Evaporator including a positive resistivity temperature coefficient heater

Abstract

The evaporator device includes a housing having an air inlet (105), a heating element (110) within the housing, and a heat exchanger. The heating element comprises a nonlinear positive temperature coefficient of resistivity material. The heat exchanger is thermally coupled to the heating element and arranged to receive an airflow from the air inlet. The heat exchanger is configured to transfer heat between the heating element and the airflow to generate a heated airflow. The heated airflow leaving the heat exchanger is configured to evaporate an evaporable material (155). Related devices, systems, techniques, and articles are also described.

Description

[0001] This invention patent application is a divisional application of the Chinese invention patent application CN202080008599.7 (International Application No. PCT / US2020 / 013224) filed on January 10, 2020, with the invention name “Evaporator including a positive resistivity temperature coefficient heater”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims priority to U.S. Provisional Patent Application No. 62 / 791,709, filed on January 11, 2019, entitled “Vaporizer Including PositiveTemperature Coefficient of Resistivity Heater,” and claims priority to U.S. Provisional Patent Application No. 62 / 816,452, filed on March 11, 2019, entitled “Vaporizer Including PositiveTemperature Coefficient of Resistivity Heater,” and claims priority to U.S. Provisional Patent Application No. 62 / 898,522, filed on September 10, 2019, entitled “Vaporizer Including PositiveTemperature Coefficient of Resistivity Heater,” and claims priority to U.S. Provisional Patent Application No. 62 / 898,522, filed on September 10, 2020, entitled “Vaporizer Including PositiveTemperature Coefficient of Resistivity Heater,” and claims priority to U.S. Provisional Patent Application No. 62 / 816,452, filed on March 11, 2019, entitled “Vaporizer Including PositiveTemperature Coefficient of Resistivity Heater,” and claims priority to U.S. Provisional Patent Application No. 62 / 898,522, filed on September 10, 2020, entitled “Vaporizer Including PositiveTemperature Coefficient of Resistivity Heater" all of which is incorporated herein by reference in its entirety to the extent permitted. Technical Field

[0004] The subject matter described herein relates to vaporizer devices, such as portable personal vaporizer devices, for generating an inhalable aerosol from one or more vaporizable materials and including a heating element utilizing a semiconductor material having a nonlinear positive temperature coefficient of resistivity (PTCR). Background Art

[0005] A vaporizer device, which may also be referred to as an electronic vaporizer device or an e-vaporizer device, may be used to deliver an aerosol (sometimes referred to as "vapor") containing one or more active ingredients by inhalation of the aerosol by a user of the vaporizing device. An electronic cigarette, which may also be referred to as an e-cigarette, is a type of vaporizer device that is typically battery powered and can be used to simulate the experience of smoking a cigarette, but without burning tobacco or other substances. When using a vaporizer device, the user inhales an aerosol, typically referred to as vapor, which may be generated by a heating element that vaporizes (usually refers to causing a liquid or solid to at least partially convert to a gas phase) a vaporizable material, which may be a liquid, solution, solid, wax, or any other form that is compatible with use with a particular vaporizer device.

[0006] In order to receive the inhalable aerosol produced by the vaporizer device, in some examples, the user can activate the vaporizer device by suction, by pressing a button or by some other method. Suction, as a commonly used term (and also used in this article), refers to being inhaled by the user in the following manner, the manner in which a certain volume of air is inhaled through the vaporizer device, so that the vaporized vaporizable material is combined with the air to produce an inhalable aerosol. A typical method for producing an inhalable aerosol from a vaporizable material in a vaporizer device (e.g., it may include an air inlet, an air outlet combined with a mouthpiece fluid, and a vaporization chamber located therebetween) includes heating the vaporizable material in a vaporization chamber (sometimes also referred to as a heating chamber), so that the vaporizable material is converted into a gas (vapor) phase. The vaporization chamber generally refers to an area or volume in a vaporizer device, in which a heat source heats the vaporizable material to produce a mixture of air and vaporizable material, reaching a certain balance between a gas phase and a condensed phase (e.g., liquid and / or solid).

[0007] Certain components of the vaporizable material in the gas phase may condense after evaporation due to cooling and / or pressure changes, thereby forming an aerosol comprising condensed phase (e.g., liquid and / or solid) particles suspended in at least some of the air drawn into the vaporizer device by puffing. If the vaporizable material includes semi-volatile compounds (e.g., compounds such as nicotine that have a relatively low vapor pressure at the inhalation temperature and pressure), the inhalable aerosol may include semi-volatile compounds in some local equilibrium between the gas phase and the condensed phase. Summary of the invention

[0008] In one aspect, the evaporator device includes a housing including an air inlet. The evaporator device also includes a heating element within the housing. The heating element includes a nonlinear positive resistivity temperature coefficient material. The evaporator device also includes a heat exchanger, which is thermally coupled to the heating element and arranged to receive an airflow from the air inlet. The heat exchanger is configured to transfer heat between the heating element and the airflow to generate a heated airflow. The heated airflow leaving the heat exchanger is configured to evaporate the evaporable material.

[0009] One or more of the following features may be included in any feasible combination. For example, the heat exchanger may include a first heat exchanger thermally coupled to a first side of the heating element. The heat exchanger may include a second heat exchanger thermally coupled to a second side of the heating element. The heat exchanger may include a plurality of fin features. The heat exchanger may be made of aluminum, copper, steel, stainless steel, or titanium. The heat exchanger may be made by extrusion of a thermally conductive material. The device may include a diverter located in the airflow path, the diverter being configured to divert a portion of the airflow through the heat exchanger. The housing may include a heater assembly cover for accommodating the heat exchanger. The device may include a power supply configured to provide electrical energy to heat the heating element. The device may include a cartridge located downstream of the heating element and oriented to receive a heated airflow, wherein downstream is relative to the airflow. The housing may include a connector configured to couple the housing to a cartridge containing a vaporizable material. The vaporizable material may be a solid vaporizable material.

[0010] The evaporator device may include a cartridge configured to accommodate a vaporizable material. The cartridge may include a first air inlet. The housing may include a connector configured to couple the housing to the cartridge. The cartridge may include a solid vaporizable material. The cartridge may include a hopper, a liquid vaporizable material in the hopper, and a wick in fluid communication with the liquid vaporizable material, wherein the cartridge is configured to receive a heated airflow and guide the heated airflow to the wick. The cartridge may include a nozzle, and the wick may be located in an airflow path between the heating element and the mouthpiece. The cartridge may include a second air inlet, which is configured to draw a second airflow into the cartridge to mix with the heated airflow and in a condensation chamber in an airflow path downstream of a heat exchanger and vaporizable material. The cartridge may include a hopper, a liquid vaporizable material in the hopper, and a wick in fluid communication with the liquid vaporizable material. The wick may be arranged to receive a heated airflow from a heat exchanger to generate vapor and / or vaporizable material in the form of vaporization of a first aerosol. The solid vaporizable material may be arranged to receive the vapor and / or the first aerosol and generate the second aerosol. The mouthpiece may be configured to receive the second aerosol after the vapor and / or the first aerosol passes through the solid vaporizable material.

[0011] The evaporator device may include a first cartridge containing a vaporizable material, a first air inlet, and a wick. The vaporizable material may be a liquid vaporizable material and the wick may be in fluid communication with the liquid vaporizable material. The wick may be arranged to receive a heated airflow through the first air inlet from a heat exchanger to evaporate the vaporizable material to produce vapor and / or a first aerosol. The evaporator device may also include a second cartridge, which includes a solid vaporizable material and a nozzle. The solid vaporizable material may be arranged to receive vapor and / or a first aerosol to produce a second aerosol. The nozzle may be configured to receive a second aerosol after the vapor and / or the first aerosol pass through the solid vaporizable material. The first cartridge can be removably coupled to the housing. The second cartridge can be removably coupled to the housing and / or the first cartridge. The first cartridge and the second cartridge may be disposable cartridges. The second cartridge may include a second air inlet for mixing ambient temperature air with the vaporized vaporizable material after the vaporized vaporizable material passes through the solid vaporizing material. The device may comprise a fibre body arranged to receive and cool the second aerosol after the vapour and / or the first aerosol has passed through the solid vaporisable material.

[0012] The nonlinear positive temperature coefficient of resistivity material includes a resistivity transition zone in which the resistivity increases over a temperature range such that when the heating element is heated above a first temperature within the resistivity transition zone, the current from the power supply is reduced to a level that limits further temperature increase of the heating element. The resistivity transition zone may begin at a first temperature between 150°C and 350°C. The resistivity transition zone may begin at a first temperature between 220°C and 300°C. The resistivity transition zone may begin at a first temperature between 240°C and 280°C. The increase in resistivity over the temperature range of the resistivity transition zone may include an increase factor of at least 10, an increase factor of at least 100, or an increase factor of at least 1000. The increase factor characterizes the relative change in resistivity between the resistivity at a first temperature associated with the beginning of the resistivity transition zone and the resistivity at a second temperature associated with the end of the resistivity transition zone. The resistivity transition region may begin at a first temperature, and the resistivity of the heating element at a temperature below the first temperature may be between 0.2 ohm-cm and 200 ohm-cm, between 2.0 ohm-cm and 20 ohm-cm, or between 20 ohm-cm and 200 ohm-cm.

[0013] The device can include a power supply configured to provide a current between 3 volts and 50 volts to the heating element, a pressure sensor, and a controller, the controller being coupled to the pressure sensor and configured to detect suction, and in response, the power supply is electrically connected to the heating element. The housing can be cylindrical, the heating element can be cylindrical, and the heat exchanger can be cylindrical. The housing can also be rectangular, the heating element can also be rectangular, and the heat exchanger can also be rectangular. The power supply can provide direct current (DC) or alternating current (AC).

[0014] The evaporator device may include an input configured to electrically connect a power source to the PTCR heating element (PTCR heater) in response to a user input. The input may include a button. The PTCR heating element of the evaporator device is self-regulating to maintain a predetermined temperature at startup. The evaporator device does not require a pressure sensor and / or a controller coupled to the pressure sensor to electrically connect a power source to the PTCR heating element and regulate its temperature.

[0015] A method may include receiving a user input by a vaporizer device; heating a vaporizable material using the vaporization device; and generating an inhalable aerosol.

[0016] On the other hand, a PTCR heater assembly for heating an airflow of an evaporator device includes a heater assembly cover and a heat exchanger disposed in the heater assembly cover. The heat exchanger is configured to transfer heat to the airflow. A positive temperature coefficient of resistivity (PTCR) heating element is thermally coupled to the heat exchanger. The PTCR heating element is configured to be electrically coupled to a power source to receive an electric current and heat a vaporizable material to form an aerosol. The PTCR heating element includes a PTCR material having a resistivity that varies based on temperature. The resistivity includes a resistivity transition zone in which the resistivity increases within a certain temperature range, so that when the PTCR heating element is heated to a first temperature above the transition zone, the current from the power source is reduced to a level that limits further temperature rise of the PTCR heating element.

[0017] One or more of the following features may be included in any feasible combination. For example, the heat exchanger may include a first heat exchanger thermally coupled to a first side of the heating element. The heat exchanger may include a second heat exchanger thermally coupled to a second side of the heating element. The heat exchanger may include a plurality of fin features. The heat exchanger may be made of aluminum, copper, steel, stainless steel, or titanium. The heat exchanger may be extruded from a thermally conductive material. The heat exchanger may be made of a foamed metal (metal foam), such as foamed aluminum. The heater assembly cover may include a non-conductive material. The heater assembly cover may include a non-conductive material. The heater assembly cover may include a metal having a non-conductive coating that isolates the heater assembly cover from the heat exchanger. The heater assembly cover may contain polytetrafluoroethylene (PTFE).

[0018] The resistivity transition zone may begin at a first temperature between 150°C and 350°C. The resistivity transition zone may also begin at a first temperature between 220°C and 300°C. The resistivity transition zone may also begin at a first temperature between 240°C and 280°C. The first temperature may be greater than 225°C. The PTCR heating element may be heated to an operating temperature between 240°C and 280°C. The PTCR heating element may be heated to an operating temperature between 245°C and 255°C. The PTCR heating element may be heated to an operating temperature of about 250°C. The PTCR heater assembly may increase the resistivity by an increase factor of at least 10, at least 100, or at least 1000 within the temperature range of the resistivity transition zone. The increase factor characterizes the relative change in resistivity between the resistivity at a first temperature associated with the start of the resistivity transition zone and the resistivity at a second temperature associated with the end of the resistivity transition zone. The resistivity transition region may begin at a first temperature and end at a second temperature, wherein the difference between the first temperature and the second temperature is 500° C. or less, 200° C. or less, 100° C. or less, or 50° C. or less. The resistivity transition region may begin at a first temperature and the resistivity of the PTCR heating element at a temperature below the first temperature is between 0.2 ohm-cm and 2.0 ohm-cm, between 2.0 ohm-cm and 20 ohm-cm, or between 20 ohm-cm and 200 ohm-cm.

[0019] On the other hand, an evaporator device for evaporating a solid vaporizable material using a heated air flow includes a housing including an air inlet and a power supply configured to provide current at a certain voltage, and a PTCR heater assembly in the housing. The PTCR heater assembly includes a heating element in the housing and configured to be electrically coupled to the power supply to receive current. The PTCR heating element includes a PTCR material having a resistivity that varies based on temperature. The resistivity includes a resistivity transition zone in which the resistivity increases within a certain temperature range so that when the PTCR heating element is heated to a first temperature higher than that in the transition zone, the current from the power supply is reduced to a level that limits further temperature rise of the PTCR heating element. The heater assembly also includes a heat exchanger that is thermally coupled to the heating element and arranged to receive an air flow from the air inlet. The heat exchanger is configured to transfer heat between the heating element and the air flow to generate a heated air flow. The heated air flow leaving the heat exchanger is configured to evaporate the solid vaporizable material.

[0020] One or more of the following features may be included in any feasible combination. For example, a solid vaporizable material may be included in the vaporizer device. The solid vaporizable material may be a medium containing tobacco. The vaporizer device may include an input configured to electrically connect a power source to the PTCR heating element in response to a user input. The input may include a button. The vaporizer device may not include a controller. The vaporizer device may not include a pressure sensor. On the other hand, the vaporizer device includes a pressure sensor and a controller coupled to the pressure sensor and configured to detect inhalation and, in response, electrically connect the power source to the PTCR heating element. The heat exchanger may include a first heat exchanger thermally coupled to a first side of the heating element. The heat exchanger may include a second heat exchanger thermally coupled to a second side of the heating element. The heat exchanger may include a plurality of fin features. The heat exchanger may be made of aluminum, copper, steel, stainless steel, or titanium. The heat exchanger may be made of extruded thermally conductive material. The heat exchanger may be made of foamed metal, such as foamed aluminum. The PTCR heater assembly may include a heater assembly cover. The heater assembly cover may include a non-conductive material. The heater assembly cover may include a non-conductive material. The heater assembly cover may include a metal having a non-conductive coating that isolates the heater assembly cover from the heat exchanger.The heater assembly cover may include polytetrafluoroethylene (PTFE).

[0021] The resistivity transition zone may begin at a first temperature between 150°C and 350°C. The resistivity transition zone may also begin at a first temperature between 220°C and 300°C. The resistivity transition zone may also begin at a first temperature between 240°C and 280°C. The first temperature may be greater than 225°C. The PTCR heating element may be heated to an operating temperature between 240°C and 280°C. The PTCR heating element may be heated to an operating temperature between 245°C and 255°C. The PTCR heating element may be heated to an operating temperature of about 250°C. The PTCR heater assembly may increase the resistivity by an increase factor of at least 10, at least 100, or at least 1000 within the temperature range of the resistivity transition zone. The increase factor characterizes the relative change in resistivity between the resistivity at a first temperature associated with the beginning of the resistivity transition zone and the resistivity at a second temperature associated with the end of the resistivity transition zone. The resistivity transition region may begin at a first temperature and end at a second temperature, wherein the difference between the first temperature and the second temperature is 500° C. or less, 200° C. or less, 100° C. or less, or 50° C. or less. The resistivity transition region may begin at a first temperature and the resistivity of the PTCR heating element at a temperature below the first temperature is between 0.2 ohm-cm and 2.0 ohm-cm, between 2.0 ohm-cm and 20 ohm-cm, or between 20 ohm-cm and 200 ohm-cm.

[0022] On the other hand, a method of evaporating a vaporizable material includes receiving a user input through a vaporizer device and heating an airflow using a PTCR heater assembly to generate a heated airflow, the PTCR heater assembly including a heat exchanger thermally coupled to the PTCR heater. The PTCR heating element is configured to be electrically coupled to a power source. The PTCR heating element includes a resistivity that varies based on temperature. The resistivity includes a resistivity transition zone, which includes an increase in resistivity within a temperature range from a first temperature to a second temperature, so that when the PTCR heating element is heated between the first temperature and the second temperature, the current from the power supply is reduced to a level that limits the further temperature increase of the PTCR heating element due to the current. The method also includes evaporating the vaporizable material with the heated airflow. The vaporizable material may include nicotine.

[0023] The details of one or more variations of the subject matter described herein are set forth in the accompanying drawings and the description below. Other features and advantages of the subject matter described herein will become more apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The thermoelectric behavior within the isotropic PTCR material is explained;

[0025] Figure 2 is a block diagram illustrating an exemplary evaporator device that can utilize convection heating to provide uniform heating of a vaporizable material according to some embodiments of the current subject matter;

[0026] Figure 3 is a block diagram of an exemplary vaporizer apparatus and cartridge with liquid vaporizable material that can provide uniform heating of the vaporizable material using convection heating;

[0027] Figure 4 is a cross-sectional view of an exemplary evaporator device having a liquid vaporizable material.

[0028] Figure 5 is a cross-sectional view of an exemplary vaporizer device having a solid vaporizable material (e.g., a heat not burn product);

[0029] Figure 6 is a block diagram of an exemplary vaporizer apparatus and cartridge having liquid vaporizable material and solid vaporizable material that can provide uniform heating of the vaporizable material using convection heating;

[0030] Figure 7 is a block diagram of an exemplary vaporizer apparatus having multiple cartridges;

[0031] Figure 8 is a cross-sectional view of an exemplary evaporator device having both liquid vaporizable material and solid vaporizable material.

[0032] Fig. 9 is a graph illustrating an exemplary resistivity versus temperature curve for a nonlinear positive temperature coefficient of resistivity (PTCR) material;

[0033] Fig.10 Presented Fig. 9 A table of resistivity versus temperature curve data of nonlinear PTCR semiconductor materials shown;

[0034] Fig.11 is a graph illustrating an exemplary resistivity versus temperature curve for a nonlinear positive temperature coefficient of resistivity (PTCR) material;

[0035] Fig. 12A is a diagram showing an exemplary PTCR heating element capable of improving evaporator heating;

[0036] Fig. 12B yes Fig. 12A A cross section of an exemplary PTCR heating element is shown;

[0037] FIG. 13A to FIG. 13E Modeled temperatures for an exemplary PTCR heater are shown;

[0038] FIG. 14A to FIG. 14F Modeled temperatures for an exemplary PTCR heater are shown;

[0039] Fig.15 shows the modeled temperature of an exemplary heater after voltage is applied for 6.0 seconds under free convection conditions;

[0040] Fig.16A shows the modeled surface temperature of an exemplary heater as a function of time;

[0041] Fig. 16B shows the modeled and measured maximum surface temperature as a function of time for an exemplary heater;

[0042] Fig. 16C shows the modeled and measured average surface temperature of an exemplary heater as a function of time;

[0043] Fig.17 shows the transient current response of an exemplary heater as a function of time;

[0044] Fig.18 is a perspective view of an exemplary evaporator assembly including a PTCR heater and a heat exchanger element capable of achieving convective heating and improving uniform heating of a vaporizable material;

[0045] Fig.19 is an exploded view of a rectangular PTCR evaporation device including an exploded view of an exemplary evaporator assembly;

[0046] Fig. 20 is a perspective view of an exemplary PTCR evaporation assembly;

[0047] Fig.21 is a perspective view of an exemplary PTCR evaporation assembly and disposable rectangular product;

[0048] Fig. 22 is a perspective view of an exemplary PTCR evaporation assembly and disposable rectangular product after 0.2 seconds of activation;

[0049] Fig.23 is a perspective view of an exemplary PTCR evaporation assembly and disposable rectangular product after 0.5 seconds of activation;

[0050] Fig.24 is a perspective view of an exemplary PTCR evaporation assembly and disposable rectangular product after 1.0 second of activation;

[0051] Fig.25 is a perspective view of an exemplary PTCR evaporation assembly and disposable rectangular product after 2.0 seconds of activation;

[0052] Fig.26 is a perspective view of an exemplary PTCR evaporation assembly and disposable rectangular product after 3.0 seconds of activation;

[0053] Fig. 27 is a perspective view of an exemplary PTCR heater having a cylindrical geometry;

[0054] Fig.28 is an exploded view showing a cylindrical exemplary PTCR heater;

[0055] Fig.29 is a perspective view of an exemplary assembled PTCR heater;

[0056] Fig.30 is a perspective view of an exemplary PTCR evaporation device with the outer cover and cylindrical diverter removed;

[0057] Fig.31 is a perspective view of an exemplary PTCR evaporation device;

[0058] Fig.32 is a graph of logarithm of resistivity versus temperature for a cylindrical exemplary evaporation device having a PTCR heater;

[0059] Fig.33 is a cross-sectional view showing a temperature simulation of an exemplary embodiment of a cylindrical evaporation device with a PTCR heater; and

[0060] FIG. 34A to FIG. 34Gis a diagram showing the transient response of temperature as a colored shear plot for an exemplary embodiment of a cylindrical evaporation device with a PTCR heater.

[0061] Like reference numbers in the drawings refer to like elements wherever possible. DETAILED DESCRIPTION

[0062] Some aspects of the current subject matter relate to an evaporator heater using a nonlinear positive temperature coefficient of resistivity (PTCR) heating element (also referred to as a PTCR heater) as a convection heater. In such a convection heater for an evaporator, air is heated by the heating element and passes through or through a vaporizable material to form a vapor and / or aerosol for inhalation. In an embodiment, the vaporizable material may include a solid vaporizable material (e.g., a loose tobacco leaf material commonly used in a heat-not-burn (HNB) vaporizer) and / or a liquid vaporizable material (e.g., a pre-filled cartridge, pod, and the like). The PTCR heating element for convection heating can make the heating of the vaporizable material more uniform. Improving heating uniformity can provide many advantages, including avoiding temperature differences within the vaporizable material acting as an insulator, preventing contamination of the heating element, and the like. And because the heating element can be formed of a PTCR material, the heating element can be temperature self-limited and will not heat above a specific temperature within a known applied voltage range, thereby avoiding the formation of unwanted and potentially dangerous chemical byproducts.

[0063] The thermoelectric power generation in the isotropic PTCR material is characterized in that for the isotropic PTCR material subjected to a voltage gradient Each control volume Control volume The temperature is heated to a temperature within the PTCR transition zone and maintained at that temperature In a wide range, such as Figure 1 Thermal power generation can be expressed as: Where P is the thermal power generation and vol is the control volume (e.g. ), and ρ is the resistivity.

[0064] By utilizing a PTCR heating element, some embodiments may allow temperature to be controlled over a range of applied voltages and do not require temperature sensors, electronic circuits, microprocessors, and / or algorithms to provide power control to the heating element.

[0065] As used herein, the term solid vaporizable material generally refers to a vaporizable material comprising a solid material. For example, some vaporizer devices heat materials derived from plant leaves or other plant components to extract aromatics and other products of plant-specific flavor as steam. These plant materials can be chopped and mixed with a variety of plant products including tobacco into a homogenized structure, in which case nicotine and / or nicotine compounds can be produced and delivered to the user of this vaporizer device in the form of an aerosol. The homogenized structure can also include vaporizable liquids, such as propylene glycol and glycerine, to increase the vapor density and aerosol produced during heating. In order to avoid producing unwanted harmful or potentially harmful components (HPHC), this type of vaporizer device benefits from a heater with a temperature control device. This vaporizer device that heats plant leaves or homogenized structures as described above so that the temperature remains below the combustion level is generally referred to as a heat-not-burn (HNB) device.

[0066] As used herein, the term liquid vaporizable material generally refers to a vaporizable material that does not contain solid materials. The liquid vaporizable material may include, for example, a liquid, a solution, a wax, or any other form that is compatible with the use of a particular vaporizer device. In an embodiment, the liquid vaporizable material may include any form suitable for using a wick or a wicking element to draw the vaporizable material into a vaporization chamber. The liquid vaporizable material may include plant-derived ingredients, such as nicotine and / or nicotine compounds. The liquid vaporizable material may include vaporizable liquids, such as propylene glycol and glycerol.

[0067] The vaporizer device operates in such a manner that the vaporizable material is heated to a suitable temperature to produce an aerosol, but without burning or charring the vaporizable material. One type of vaporizer device is more complex because it utilizes relatively tight temperature control to prevent overheating and the associated formation of HPHCs. Due to the inherent non-uniformity of the vaporizable material to be heated and the associated spatially non-uniform thermal properties, this complexity typically requires electronic circuitry including a microprocessor, which is often difficult in HNB devices. This can result in over-temperature areas and potential HPHC generation. And some existing solutions are unable to control the local temperature within the vaporizer device, resulting in a high probability of vaporizable material and HPHC generation in over-temperature areas.

[0068] Another type of evaporator device is simpler in that no temperature control means are provided, making the evaporator device potentially cheaper to construct but involving the risk of overheating and thereby causing unwanted chemical by-products.

[0069] In HNB evaporator devices (e.g., where the vaporizable material is solid), some existing approaches lack the ability to apply uniform temperature due to one or more of the following reasons. For example, the solid vaporizable material to be heated has a low thermal diffusivity, so that diffusion of high temperature from the heating element into the solid vaporizable material is both slow and results in high thermal gradients. As a result, non-uniform heating may be an unavoidable result. As another example, if heating element temperature control is employed, the heating element temperature control typically processes an average temperature, so that heating of a non-uniform solid vaporizable material by high temperature within the heating element may result in high temperature within the solid vaporizable material. As yet another example, in order to allow heating of the insulating material, some existing HNB devices require a warm-up time equal to or greater than 30 seconds, with attendant costs in terms of energy consumption, battery consumption, and user inconvenience.

[0070] In evaporator devices that evaporate a fluid by bringing the heating element into contact with the fluid to be evaporated, contamination of the heating element may occur, resulting in possible impairment of performance. A solution to this problem may be to incorporate the heating element into the disposable part of the evaporator, so that the heating element is replaced with each new disposable part, thereby limiting but not eliminating contamination of the heating element.

[0071] To overcome the difficulty of uniformly heating the vaporizable material, some embodiments of the present subject matter can use one or more PTCR heating elements in combination with a heat exchanger to preheat the air. When the user draws air into the vaporizer device, the incoming airflow is heated to a controlled temperature when passing through the heat exchanger, and then passes through or crosses the vaporizable material to be heated. The vaporizable material can be a solid material (e.g., as in the HNB material) or a liquid (e.g., a fluid together with a porous wick). In an embodiment, the airflow can pass through the heat exchanger, then pass through and / or through a porous wick filled with liquid vaporizable material, then pass through a solid vaporizable material (e.g., HNB material), and then reach the user. In an embodiment, a geometry for cooling air inflow can be included between the wick and the user, such as a balanced air inlet (i.e., a second air inlet). In addition, the present subject matter can provide a PTCR heater with inherent temperature control, for example, for a given range of power supply voltages (which can vary by a factor of ten or more in some embodiments), the designed peak temperature will not be exceeded. Compared with some traditional methods, this method can lead to improvements in uniform heating of vaporizable materials.

[0072] Additionally, using this convection heating method, the PTCR heating element can be placed upstream of the wick, fluid container, and / or vaporizable material, making the PTCR heating element completely removable from any disposable components of the mechanism. By including the PTCR heating element in the non-disposable portion of the vaporizer device, unnecessary waste can be avoided.

[0073] Figure 2 1 is a block diagram illustrating an exemplary evaporator device 100 that can provide uniform heating of a vaporizable material using convection heating according to some embodiments of the current subject matter. The exemplary evaporator device 100 includes an air inlet 105, a PTCR heater 110 with a heat exchanger, and a power source 115, such as a battery, a capacitor, and / or the like. The exemplary evaporator device 100 may include a housing 120 that may be coupled to one or more of the PTCR heater 110 with a heat exchanger and the power source 115. In embodiments, the exemplary evaporator device 100 may include an optional controller 102 and an optional pressure sensor 107. In embodiments, the housing 120 may define the air inlet 105.

[0074] The PTCR heater 110 with a heat exchanger may include a heating element formed of a PTCR material, which will be described in more detail below. The heat exchanger may be thermally coupled to the heating element and may be configured to transfer heat between the heating element and an airflow passing through and / or through the PTCR heater 110 with a heat exchanger to produce a heated airflow. The PTCR heater 110 with a heat exchanger may include a plurality of heat exchangers, for example, coupled to different sides of the heating element, and may include a flow divider for diverting the airflow through and / or over the fins of the heat exchanger to improve heat transfer. Figures 9 to 34G An exemplary PTCR heater 110 with a heat exchanger is discussed in greater detail.

[0075] The exemplary vaporizer device 100 may include a connector 117 ( Figure 4 , Figure 5 and Figure 8 ), for coupling the housing 120 to one or more cartridges 125 including vaporizable material 130. In an embodiment, the cartridge 125 may include a nozzle 135. In an embodiment, the coupling may be released so that a user can easily couple and detach the cartridge 125 to and from the vaporizer device 100 via the connector 117.

[0076] When the evaporator device 100 is coupled to the cartridge 125 , the evaporator device 100 and the cartridge 125 may be arranged to define an airflow path from the air inlet 105 , through and / or over the PTCR heater 110 with a heat exchanger, through the first air inlet of the cartridge, through the vaporizable material 130 , and out of the nozzle 135 .

[0077] An optional controller 102 (e.g., a processor capable of executing logic, circuitry, etc.) is used to control the transfer of heat to cause the vaporizable material to transition from a condensed form (e.g., a solid, a liquid, a solution, a suspension, a portion of at least partially unprocessed plant material, etc.) to a vapor phase. The optional controller can be part of one or more printed circuit boards (PCBs) consistent with certain embodiments of the current subject matter.

[0078] The power source 115 may include any power source suitable for applying power to the PTCR heater with heat exchanger 110. For example, the power source 115 may include a battery, a capacitor (even with resistor-capacitor (RC) decay), and / or the like. In an embodiment, the power source 115 may provide a voltage selected from a wide range of voltages. For example, in some embodiments, the power source 115 may provide a voltage between 3 volts and 50 volts or higher. In an embodiment, the voltage provided to the PTCR heater with heat exchanger 110 may vary by an order of magnitude with little effect on the performance of the PTCR heater with heat exchanger 110. In an embodiment, the power source 115 may include a plurality of power sources, which may be selected based on operating conditions and / or desired evaporator device performance.

[0079] In operation, a user may draw air through the mouthpiece 135 (e.g., puff), which may be detected by the optional controller 102 using the optional pressure sensor 107. In response to detecting the puff, the optional controller 102 may cause current from the power supply 115 to be applied to the PTCR heater with heat exchanger 110, thereby heating the PTCR heater with heat exchanger 110. Because the PTCR heater with heat exchanger 110 is formed of PTCR material, the heating will be self-limiting and the heating element will not overheat.

[0080] The air flow passes through the air inlet 105 and passes over and / or through the PTCR heater 110 with a heat exchanger, so that the air in the air flow is uniformly heated. The heated air flow continues to reach the vaporizable material 130, so that the vaporizable material 130 is also uniformly heated and forms a vapor (gas). The vaporizable material 130 may include a liquid, a solution, a solid, a wax, or any other form. In an embodiment, the incoming air passing along the air flow path passes over, through, and in a similar manner passes through an area or chamber (e.g., an atomizer) in which the vaporizable material in the gas phase is entrained in the air.

[0081] The entrained gas phase vaporizable material may condense as it passes through the rest of the airflow path, so that the vaporizable material in the form of an inhalable dose of an aerosol can be delivered to the mouthpiece 135 for the user to inhale in the form of vapor and / or aerosol. In an embodiment, the cartridge 125 includes a balanced air inlet (i.e., a second air inlet) 140, which can be used to provide ambient temperature air to mix with the heated airflow entering the cartridge through the first air inlet. Ambient temperature air can be mixed with the heated airflow in the condensation chamber. The balanced air inlet 140 is positioned after the heated airflow passes through the vaporizable material (e.g., downstream of the heat exchanger and the vaporizable material), thereby cooling the heated airflow before the user inhales. In an embodiment, the balanced air inlet 140 is integrated with the mouthpiece 135.

[0082] Activation of the PTCR heating element may be initiated by automatically detecting a puff based on one or more signals generated by one or more sensors, such as the optional pressure sensor 107 or a sensor configured to detect a change in pressure relative to ambient pressure (or optionally measure absolute pressure) along an airflow path, one or more motion sensors of the evaporator, one or more flow sensors of the evaporator, a capacitive lip sensor of the evaporator; receiving a signal from a computing device in communication with the evaporator in response to detecting user interaction with one or more input devices (e.g., a button or other tactile control device of the evaporator, such as a manual toggle switch, a push button switch, a pressure switch, etc.); and / or determining by other methods that a puff is occurring or is about to occur.

[0083] As mentioned in the previous paragraph, a vaporizer consistent with embodiments of the current subject matter can be configured to connect (e.g., wirelessly or through a wired connection) to a computing device (or optionally two or more devices) that communicates with the vaporizer. To this end, the optional controller 102 can include communication hardware. The optional controller 102 can also include memory. The computing device can be a component of a vaporizer system that also includes a vaporizer, and the computing device can include its own communication hardware that can establish a wireless communication channel with the communication hardware of the vaporizer. For example, a computing device used as part of a vaporizer system can include a general-purpose computing device (e.g., a smartphone, a tablet computer, a personal computer, some other portable device, such as a smart watch, etc.) that executes software to generate a user interface so that a user of the device interacts with the vaporizer. In other embodiments of the current subject matter, such a device used as part of a vaporizer system can be dedicated hardware, such as a remote control or other wireless or wired device with one or more physical or software interface controls (e.g., configurable on a screen or other display device, and can be controlled by a user with a touch-sensitive screen or some other input device (such as a mouse, pointer, trackball, cursor buttons, etc.)). The vaporizer may also include one or more output features or devices for providing information to a user.

[0084] A computing device as part of a vaporizer system as defined above may be used for any of one or more functions, such as dose control (e.g., dose monitoring, dose setting, dose limiting, user tracking, etc.), session control (e.g., session monitoring, session setting, session limiting, user tracking, etc.), nicotine delivery control (e.g., switching between nicotine and non-nicotine vaporizable materials, adjusting the amount of nicotine delivered, etc.), obtaining location information (e.g., the location of other users, the location of retailers / business locations, the location of vaping, the relative or absolute location of the vaporizer itself, etc.), vaporizer personalization (e.g., naming the vaporizer, locking / password protecting the vaporizer, adjusting one or more parental controls, associating the vaporizer with a user group, registering the vaporizer with a manufacturer or warranty maintenance organization, etc.), engaging in social activities with other users (e.g., gaming, social media communications, interacting with one or more groups, etc.), etc. The terms "conducting a session," "session," "vaporizer session," or "vapor session" are generally used to refer to a period of time dedicated to using a vaporizer. The period may include a time period, a number of doses, an amount of vaporizable material, etc.

[0085] In examples where the computing device provides signals associated with activation of the PTCR heating element, or in other examples where the computing device is coupled to the vaporizer to implement various control or other functions, the computing device executes one or more sets of computer instructions to provide a user interface and underlying data processing. In one example, detection of user interaction with one or more user interface elements by the computing device may cause the computing device to signal the vaporizer to activate the PTCR heating element to a full operating temperature for producing an inhalable dose of vapor / aerosol. Other functions of the vaporizer may be controlled by user interaction with a user interface on a computing device in communication with the vaporizer.

[0086] The temperature of the PTCR heating element of the vaporizer may depend on a variety of factors, including conductive heat transferred to other parts of the electronic vaporizer and / or the environment, latent heat loss due to evaporation of the vaporizable material from the wicking element as a whole and / or the atomizer, and convective heat loss due to airflow (e.g., air moving through the heating element as a whole or the atomizer when the user inhales on the electronic vaporizer). As described above, in order to reliably activate the PTCR heating element or heat the PTCR heating element to a desired temperature, in some embodiments of the subject matter, the vaporizer may utilize a signal from an optional pressure sensor 107 to determine when the user inhales. The optional pressure sensor 107 may be positioned in the airflow path and / or may be connected (e.g., by a channel or other path) to the airflow path, which connects the air inlet 105 (for air to enter the device) and the outlet (e.g., in the mouthpiece 135) through which the user inhales the generated vapor and / or aerosol, so that the optional pressure sensor experiences a pressure change while the air passes from the air inlet 105 through the vaporizer device to the air outlet. In embodiments of the current subject matter, the PTCR heating element may optionally be activated in association with a puff by a user, such as by automatically detecting a puff, such as by detecting a pressure change in the airflow path via optional pressure sensor 107. In embodiments, a switch is an input device that can be used to electrically complete a circuit between a power source and the PTCR heating element. In embodiments, the input device includes a relay, a solenoid, and / or a solid-state device that can be used to electrically complete a circuit between a power source and the PTCR heating element to activate the vaporizer device.

[0087] Typically, the optional pressure sensor 107 (and any other sensor) can be located on or coupled to the optional controller 102 (e.g., a printed circuit board assembly or other type of circuit board) (e.g., electrically or electronically connected, physically connected or wirelessly connected). In order to accurately measure and maintain the durability of the evaporator, it is beneficial to provide an elastic seal to separate the airflow path from the rest of the evaporator. The seal (which can be a gasket) can be configured to at least partially surround the optional pressure sensor 107 so that the connection of the optional pressure sensor 107 to the internal circuit of the evaporator is separated from the portion of the optional pressure sensor 107 exposed to the airflow path. In the example of an evaporator based on a cartridge, the seal or gasket can also separate the portion of one or more electrical connections between the evaporator body and the evaporator cartridge. This arrangement of gaskets or seals in the evaporator can help mitigate the potential destructive effects of interactions with environmental factors (e.g., water in the vapor phase or liquid phase, other fluids (e.g., evaporable materials, etc.) on the evaporator components, and / or reduce the escape of air from the airflow path designed in the evaporator. Unwanted air, liquids, or other fluids passing through and / or contacting the circuitry of the evaporator may result in various undesirable effects, such as altered pressure readings, and / or may result in the accumulation of undesirable materials (e.g., moisture), vaporizable materials, etc., in various portions of the evaporator, which may result in poor pressure signals, degradation of the optional pressure sensor or other components, and / or shortened life of the evaporator. Leaks in seals or gaskets may also result in a user inhaling air that passes through portions of the evaporator device that contain or are constructed of materials that may be unsuitable for inhalation.

[0088] In an embodiment, the cartridge 125 may include a fiber body that is used to cool the heated airflow after it passes through the vaporizable material 130 .

[0089] As described above, the vaporizable material 130 may include a solid vaporizable material (eg, HNB material) and / or a liquid vaporizable material (eg, a liquid, a solution, etc.). Figure 31 is a block diagram of an exemplary evaporator device 100 and a cartridge 125 with a liquid vaporizable material, which can provide uniform heating of the vaporizable material using convection heating. The vaporizable material 130 includes an atomizer, which includes a porous wick 150 in fluid communication with a fluid tank or reservoir 145. The porous wick 150 is located in the path of the heated airflow between the PTCR heater 110 with a heat exchanger and the nozzle 135. The porous wick 150 is positioned so that the heated airflow passes through and / or passes through the porous wick 150 in operation, and the porous wick 150 is filled to saturation with the vaporizable fluid, and the liquid vaporizable material filled with the porous wick 150 evaporates to form a vapor and / or aerosol. In an embodiment, the porous wick 150 can allow air to enter the reservoir 145 to replace the removed liquid volume. In other words, capillary action pulls the liquid vaporizable material into the porous wick 150 to be vaporized by the heated air flow, and in some embodiments of the present subject matter, air can return through the wick to the reservoir 145 to at least partially equalize the pressure in the reservoir 145. Other methods of allowing air to return to the reservoir 145 to equalize the pressure are also within the scope of the current subject matter. Figure 4 is a cross-sectional view of an exemplary evaporator device having a liquid evaporable material, and Figure 5 is a cross-sectional view of an exemplary evaporator apparatus having a solid vaporizable material (eg, HNB product).

[0090] In an embodiment, the vaporizable material 130 may include both liquid vaporizable material and solid vaporizable material. Figure 6 1 is a block diagram of an exemplary vaporizer device 100 and a cartridge 125 having a liquid vaporizable material and a solid vaporizable material, which can provide uniform heating of the vaporizable material using convection heating. The vaporizable material 130 includes a reservoir 145, in which a liquid vaporizable material is contained; a wick 150 in fluid communication with the liquid vaporizable material, and a solid vaporizable material 155 located downstream (relative to the airflow) of the porous wick 150. The porous wick 150 is arranged to receive a heated airflow from a heater 110 with a heat exchanger to vaporize the vaporizable material to produce vapor and / or a first aerosol. The solid vaporizable material 155 is arranged to receive vapor and / or a first aerosol from the wick and produce a second aerosol. The mouthpiece 135 is configured to receive a second aerosol after the vaporized vaporizable material passes through the solid vaporizable material 155. By combining both the liquid vaporizable material and the solid vaporizable material, an improved taste can be achieved. Furthermore, by utilizing convective heating via the PTCR material to vaporize both the liquid vaporizable material and the solid vaporizable material, only a single heater is required to heat both materials.

[0091] In embodiments, the liquid vaporizable material and the solid vaporizable material may be included in different cartridges. Figure 7 6 is a block diagram of an exemplary vaporizer device 100 with multiple cartridges. A first cartridge 605 includes a liquid vaporizable material (including a reservoir 145 and a porous wick 150), and a second cartridge 610 includes a solid vaporizable material 130, which can provide uniform heating for the vaporizable material using convection heating. The first cartridge 605 can be removably coupled to the vaporizer device 100 and the second cartridge 610 can be removably coupled to the first cartridge 605. As shown, the first cartridge 605 includes a reservoir 145 (e.g., a can), a liquid vaporizable material in the reservoir 145, and a wick 150 in fluid communication with the liquid vaporizable material. When the first cartridge 605 is coupled to the vaporizer device 100, the wick 150 is arranged to receive a heated airflow from a heater 110 with a heat exchanger to evaporate the vaporizable material to produce vapor and / or a first aerosol. The second cartridge 610 includes a solid vaporizable material 130, a balancing air inlet 140, and a nozzle 135. When the second cartridge 610 is coupled to the first cartridge, the solid vaporizable material 130 is arranged to receive vapor and / or aerosol from the wick 150 and generate a second aerosol. The nozzle 135 is configured to receive the second aerosol after the vapor and / or the first aerosol passes through the solid vaporizable material 155. In an embodiment, the balancing air inlet (i.e., the second air inlet) 140 can provide ambient temperature air for cooling the heated first aerosol that has passed through the solid vaporizable material 155. Figure 8 is a cross-sectional view of an exemplary evaporator device with both liquid vaporizable material and solid vaporizable material.

[0092] Compared with conventional conduction heating methods, this convection heating method can provide several advantages for evaporating solid materials (e.g., HNB materials). For example, instead of poorly conducting into insulating materials (e.g., solid vaporizable materials) along the direction orthogonal to the airflow, generating volatiles and differential porosity of the vaporizable materials to be heated, some embodiments of the present subject matter can provide incoming preheated air, which enters the vaporizable material uniformly as ripples that uniformly cover the cross-section of the vaporizable material. The volatiles are then released in a direction parallel to the flow of the heated air, while the porosity increases. As another example, due to the uniform release of the cross-section of the volatiles and the simultaneous increase in porosity, the problem of differential flow paths can be eliminated in some embodiments. As another example, the problem of deterioration of conductive heat transfer through the product can be eliminated in some embodiments of the current subject matter. As another example, some embodiments of the current subject matter can eliminate the previously required preheating period, so that the current subject matter can provide an aerosol on demand from the heated vaporizable material.

[0093] Similarly, this convection heating method can provide several advantages for vaporizing liquid vaporizable materials. For example, instead of applying heat directly to the liquid vaporizable material using a heating element in direct contact with the liquid vaporizable material, some embodiments of the present subject matter can provide incoming preheated air as corrugations that evenly cover a cross-section of a porous wick saturated with the fluid to be vaporized, thereby avoiding temperature differences and the potential for contamination of the heating element.

[0094] As another example, by placing the wick near and upstream (relative to the airflow) of the solid vaporizable material (eg, loose tobacco leaves), undesirable aerosol condensation within the device can be minimized.

[0095] Furthermore, the inherent temperature control behavior of the PTCR heater can simplify the power delivery circuitry because no specific thermal feedback is required. The power delivery circuitry to the PTCR heater can be further simplified by eliminating the need for a typical power delivery system to provide a relatively constant voltage from a power source. In embodiments, the applied voltage can vary by more than an order of magnitude without significantly affecting the resulting heating element temperature.

[0096] An exemplary PTCR heater will now be described in more detail. The PTCR includes a semiconductor material having a resistivity that varies nonlinearly with increasing temperature. Typical PTCR materials have a relatively low resistivity when the temperature is maintained below the temperature transition zone. Above the temperature transition zone, the resistivity of the PTCR material is higher than the resistivity of the same PTCR material at a temperature below the temperature transition zone. Within the temperature transition zone of 50 degrees Celsius or less, the resistivity change can increase by several orders of magnitude.

[0097] A heating element can utilize nonlinear PTCR materials to achieve inherent temperature control. For example, a heating element at ambient temperature can be connected to a power source that provides a voltage gradient and a resulting current. Since the resistivity of the heating element is relatively low at ambient temperature (e.g., the ambient temperature is below the transition region), current will flow through the heating element. When current flows through the nonlinear PTCR material, the resistance generates heat (e.g., dissipation of electrical energy). The generated heat causes the temperature of the heating element to increase, causing the resistivity of the heating element to change. When the temperature of the heating element reaches the transition region, the resistivity increases significantly over a small temperature range. The change in resistivity can be caused by the physical properties of the material. For example, a phase change may occur in the material. This increase in resistivity (resulting in an overall increase in resistance) reduces the current flow, thereby reducing the heat generation. The transition region includes temperatures where there is an inflection point such that the heat generated is insufficient to further increase the temperature of the heating element, thereby limiting the temperature of the heating element. As long as the power source remains connected and supplies current, the heating element will maintain a uniform temperature with minimal temperature changes. In this case, the power applied to the PTCR heating element can be given by the formula PI = Voltage 2 / resistance. The heat loss of PTCR heating element can be expressed by P L represents , and includes any combination of conduction, convection, radiation, and latent heat. During steady-state operation, P I =P L . With P L As P increases, the temperature of the PTCR heating element decreases, thereby reducing the resistance and increasing the current flowing through the PTCR heating element. L When P decreases, the temperature of the PTCR heating element increases, thereby increasing the resistance and reducing the current flowing through the PTCR heating element. L The resistance of a PTCR heating element increases logarithmically as it approaches 0. The limiting operating temperature of a PTCR heating element may be affected by the element material, element geometry, element resistivity as a function of temperature characteristics, power supply, circuit characteristics (e.g., voltage gradient, current, time-varying characteristics), and the like.

[0098] Fig. 9 is a graph illustrating an exemplary resistivity versus temperature curve for a nonlinear PTCR material. The vertical axis is logarithmic. A heating element (referred to as a PTCR heater) constructed (e.g., formed) of a nonlinear PTCR material can have advantageous properties. For example, upon application of a sufficient voltage gradient (e.g., ), the PTCR heater will generate heat and increase the temperature until it reaches the transition zone. Fig. 9 In the curve shown, the transition region spans between temperatures T1 and T2. Fig. 9 In the curves shown, the resistivity versus temperature curve is nonlinear between T1 and T2, but in other embodiments, the resistivity versus temperature curve can be close to linear or linear or other shapes. At some temperature above T1, the resistivity of the nonlinear PTCR material will increase to a point where further temperature increase will cease because the total resistance will increase to a point that limits the current. In other words, embodiments of the PTCR heater can be considered to be temperature self-limiting and, given a known range of applied voltages, will not heat beyond a temperature just above the low point T1 of the temperature transition region.

[0099] The performance of a PTCR heater can depend on Fig. 9PTCR behavior in and the geometry of the heater. A PTCR heater having a relatively long and narrow geometry and having electrical contacts for applying a differential voltage at each end of the longer dimension of the PTCR heater may be ineffective because the resistivity of the nonlinear PTCR material is generally too high at temperatures below T1. Nonlinear PTCR materials with steep transition regions (where the temperature difference between T1 and T2 is less than 10°C) may cause all voltage to drop into a small portion of the length of the long and narrow geometry, and give inevitable spatial non-uniformities within any material. Therefore, some embodiments of the PTCR heater include an electrode configuration for the PTCR heater such that a nonlinear PTCR material is provided in a parallel circuit. In some embodiments that may provide improved heating uniformity, the geometry of the PTCR heater may include a thin section of nonlinear PTCR material sandwiched between electrical conductors or conductive coatings to which a differential voltage may be applied.

[0100] Fig.10 Presented for Fig. 9Table of resistivity versus temperature curve data for non-linear PTCR semiconductor materials shown in . In an embodiment, the PTCR heating element has a resistivity between 10 ohm-cm and 100 ohm-cm at 100°C, and a resistivity between 50,000 ohm-cm and 150,000 ohm-cm at 260°C. In an embodiment, the PTCR heating element has a resistivity between 20 ohm-cm and 200 ohm-cm at 100°C, and a resistivity between 100,000 ohm-cm and 200,000 ohm-cm at 265°C. In an embodiment, the PTCR heating element has a resistivity of less than 100 ohm-cm at 100°C, and a resistivity of greater than 100,000 ohm-cm at 260°C. In an embodiment, the PTCR heating element has a resistivity of less than 100 ohm-cm at 100°C, and a resistivity of greater than 250,000 ohm-cm at 275°C. In an embodiment, the PTCR heating element has a resistivity of less than 100 ohm-cm at 100° C., and a resistivity of greater than 300,000 ohm-cm at 295° C. In an embodiment, the PTCR heating element has a resistivity between 10 ohm-cm and 110 ohm-cm at 25° C., and a resistivity between 10 ohm-cm and 110 ohm-cm at 100° C., and a resistivity between 100,000 ohm-cm and 325,000 ohm-cm at 280° C. In an embodiment, the PTCR heating element has a resistivity between 10 ohm-cm and 150 ohm-cm at 25° C., and a resistivity between 10 ohm-cm and 150 ohm-cm at 100° C., and a resistivity between 100,000 ohm-cm and 350,000 ohm-cm at 280° C. In an embodiment, the PTCR heating element has a resistivity between 10 ohm-cm and 200 ohm-cm at 25° C., and between 10 ohm-cm and 200 ohm-cm at 100° C., and between 100,000 ohm-cm and 375,000 ohm-cm at 280° C. In an embodiment, the PTCR heating element has a resistivity between 10 ohm-cm and 300 ohm-cm at 25° C., and between 10 ohm-cm and 300 ohm-cm at 100° C., and between 100,000 ohm-cm and 400,000 ohm-cm at 280° C.In an embodiment, the PTCR heating element has a resistivity between 10 ohm-cm and 400 ohm-cm at 25° C., and between 10 ohm-cm and 400 ohm-cm at 100° C., and between 100,000 ohm-cm and 450,000 ohm-cm at 280° C. In an embodiment, the PTCR heating element has a resistivity between 10 ohm-cm and 500 ohm-cm at 25° C., and between 10 ohm-cm and 500 ohm-cm at 100° C., and between 100,000 ohm-cm and 500,000 ohm-cm at 280° C. In an embodiment, the PTCR heating element has a resistivity between 50 ohm-cm and 110 ohm-cm at 25° C., and between 50 ohm-cm and 110 ohm-cm at 100° C., and between 150,000 ohm-cm and 325,000 ohm-cm at 280° C. In an embodiment, the PTCR heating element has a resistivity between 50 ohm-cm and 150 ohm-cm at 25° C., and between 50 ohm-cm and 150 ohm-cm at 100° C., and between 150,000 ohm-cm and 350,000 ohm-cm at 280° C. In an embodiment, the PTCR heating element has a resistivity between 50 ohm-cm and 200 ohm-cm at 25° C., and between 50 ohm-cm and 200 ohm-cm at 100° C., and between 150,000 ohm-cm and 375,000 ohm-cm at 280° C. In an embodiment, the PTCR heating element has a resistivity between 50 ohm-cm and 300 ohm-cm at 25° C., and between 50 ohm-cm and 300 ohm-cm at 100° C., and between 150,000 ohm-cm and 400,000 ohm-cm at 280° C. In an embodiment, the PTCR heating element has a resistivity between 50 ohm-cm and 400 ohm-cm at 25° C., and between 50 ohm-cm and 400 ohm-cm at 100° C., and between 150,000 ohm-cm and 450,000 ohm-cm at 280° C. In an embodiment, the PTCR heating element has a resistivity between 50 ohm-cm and 500 ohm-cm at 25° C., and between 50 ohm-cm and 500 ohm-cm at 100° C., and between 150,000 ohm-cm and 500,000 ohm-cm at 280° C.In an embodiment, the PTCR heating element has a resistivity between 90 ohm-cm and 110 ohm-cm at 25° C., and between 90 ohm-cm and 110 ohm-cm at 100° C., and between 200,000 ohm-cm and 325,000 ohm-cm at 280° C. In an embodiment, the PTCR heating element has a resistivity between 90 ohm-cm and 150 ohm-cm at 25° C., and between 90 ohm-cm and 150 ohm-cm at 100° C., and between 200,000 ohm-cm and 350,000 ohm-cm at 280° C. In an embodiment, the PTCR heating element has a resistivity between 90 ohm-cm and 200 ohm-cm at 25° C., and between 90 ohm-cm and 200 ohm-cm at 100° C., and between 200,000 ohm-cm and 375,000 ohm-cm at 280° C. In an embodiment, the PTCR heating element has a resistivity between 90 ohm-cm and 300 ohm-cm at 25° C., and between 90 ohm-cm and 300 ohm-cm at 100° C., and between 200,000 ohm-cm and 400,000 ohm-cm at 280° C. In an embodiment, the PTCR heating element has a resistivity between 90 ohm-cm and 400 ohm-cm at 25° C., and between 90 ohm-cm and 400 ohm-cm at 100° C., and between 200,000 ohm-cm and 450,000 ohm-cm at 280° C. In an embodiment, the PTCR heating element has a resistivity between 90 ohm-cm and 500 ohm-cm at 25° C., and between 90 ohm-cm and 500 ohm-cm at 100° C., and between 200,000 ohm-cm and 500,000 ohm-cm at 280° C. In an embodiment, the PTCR heating element has a resistivity between 10 ohm-cm and 110 ohm-cm at 50° C., and between 10 ohm-cm and 50 ohm-cm at 150° C., and between 50,000 ohm-cm and 125,000 ohm-cm at 260° C. In an embodiment, the PTCR heating element has a resistivity between 10 ohm-cm and 150 ohm-cm at 50° C., and between 10 ohm-cm and 100 ohm-cm at 150° C., and between 50,000 ohm-cm and 150,000 ohm-cm at 260° C.In an embodiment, the PTCR heating element has a resistivity between 10 ohm-cm and 200 ohm-cm at 50° C., a resistivity between 10 ohm-cm and 150 ohm-cm at 150° C., and a resistivity between 50,000 ohm-cm and 175,000 ohm-cm at 260° C. In an embodiment, the PTCR heating element has a resistivity between 10 ohm-cm and 300 ohm-cm at 50° C., a resistivity between 10 ohm-cm and 200 ohm-cm at 150° C., and a resistivity between 50,000 ohm-cm and 200,000 ohm-cm at 260° C. In an embodiment, the PTCR heating element has a resistivity between 10 ohm-cm and 400 ohm-cm at 50° C., and between 10 ohm-cm and 250 ohm-cm at 150° C., and between 50,000 ohm-cm and 250,000 ohm-cm at 260° C. In an embodiment, the PTCR heating element has a resistivity between 10 ohm-cm and 500 ohm-cm at 50° C., and between 10 ohm-cm and 300 ohm-cm at 150° C., and between 50,000 ohm-cm and 300,000 ohm-cm at 260° C. In an embodiment, the PTCR heating element has a resistivity between 50 ohm-cm and 110 ohm-cm at 50° C., and between 20 ohm-cm and 50 ohm-cm at 150° C., and between 75,000 ohm-cm and 125,000 ohm-cm at 260° C. In an embodiment, the PTCR heating element has a resistivity between 50 ohm-cm and 150 ohm-cm at 50° C., and between 20 ohm-cm and 100 ohm-cm at 150° C., and between 75,000 ohm-cm and 150,000 ohm-cm at 260° C. In an embodiment, the PTCR heating element has a resistivity between 50 ohm-cm and 200 ohm-cm at 50° C., a resistivity between 20 ohm-cm and 150 ohm-cm at 150° C., and a resistivity between 75,000 ohm-cm and 175,000 ohm-cm at 260° C. In an embodiment, the PTCR heating element has a resistivity between 50 ohm-cm and 300 ohm-cm at 50° C., a resistivity between 20 ohm-cm and 200 ohm-cm at 150° C., and a resistivity between 75,000 ohm-cm and 200,000 ohm-cm at 260° C.In an embodiment, the PTCR heating element has a resistivity between 50 ohm-cm and 400 ohm-cm at 50° C., and between 20 ohm-cm and 250 ohm-cm at 150° C., and between 75,000 ohm-cm and 250,000 ohm-cm at 260° C. In an embodiment, the PTCR heating element has a resistivity between 50 ohm-cm and 500 ohm-cm at 50° C., and between 20 ohm-cm and 300 ohm-cm at 150° C., and between 75,000 ohm-cm and 300,000 ohm-cm at 260° C. In an embodiment, the PTCR heating element has a resistivity between 75 ohm-cm and 110 ohm-cm at 50° C., and between 30 ohm-cm and 50 ohm-cm at 150° C., and between 100,000 ohm-cm and 125,000 ohm-cm at 260° C. In an embodiment, the PTCR heating element has a resistivity between 75 ohm-cm and 150 ohm-cm at 50° C., and between 30 ohm-cm and 100 ohm-cm at 150° C., and between 100,000 ohm-cm and 150,000 ohm-cm at 260° C. In an embodiment, the PTCR heating element has a resistivity between 75 ohm-cm and 200 ohm-cm at 50° C., a resistivity between 30 ohm-cm and 150 ohm-cm at 150° C., and a resistivity between 100,000 ohm-cm and 175,000 ohm-cm at 260° C. In an embodiment, the PTCR heating element has a resistivity between 75 ohm-cm and 300 ohm-cm at 50° C., a resistivity between 30 ohm-cm and 200 ohm-cm at 150° C., and a resistivity between 100,000 ohm-cm and 200,000 ohm-cm at 260° C. In an embodiment, the PTCR heating element has a resistivity between 75 ohm-cm and 400 ohm-cm at 50° C., a resistivity between 30 ohm-cm and 250 ohm-cm at 150° C., and a resistivity between 100,000 ohm-cm and 250,000 ohm-cm at 260° C. In an embodiment, the PTCR heating element has a resistivity between 75 ohm-cm and 500 ohm-cm at 50° C., a resistivity between 30 ohm-cm and 300 ohm-cm at 150° C., and a resistivity between 100,000 ohm-cm and 300,000 ohm-cm at 260° C.In an embodiment, the PTCR heating element has a resistivity between 10 ohm-cm and 110 ohm-cm at 25° C., and between 10 ohm-cm and 50 ohm-cm at 150° C., and between 100,000 ohm-cm and 325,000 ohm-cm at 280° C. In an embodiment, the PTCR heating element has a resistivity between 10 ohm-cm and 150 ohm-cm at 25° C., and between 10 ohm-cm and 100 ohm-cm at 150° C., and between 100,000 ohm-cm and 350,000 ohm-cm at 280° C. In an embodiment, the PTCR heating element has a resistivity between 10 ohm-cm and 200 ohm-cm at 25° C., a resistivity between 10 ohm-cm and 150 ohm-cm at 150° C., and a resistivity between 100,000 ohm-cm and 375,000 ohm-cm at 280° C. In an embodiment, the PTCR heating element has a resistivity between 10 ohm-cm and 300 ohm-cm at 25° C., a resistivity between 10 ohm-cm and 200 ohm-cm at 150° C., and a resistivity between 100,000 ohm-cm and 400,000 ohm-cm at 280° C. In an embodiment, the PTCR heating element has a resistivity between 10 ohm-cm and 400 ohm-cm at 25° C., and between 10 ohm-cm and 250 ohm-cm at 150° C., and between 100,000 ohm-cm and 450,000 ohm-cm at 280° C. In an embodiment, the PTCR heating element has a resistivity between 10 ohm-cm and 500 ohm-cm at 25° C., and between 10 ohm-cm and 300 ohm-cm at 150° C., and between 100,000 ohm-cm and 500,000 ohm-cm at 280° C. In an embodiment, the PTCR heating element has a resistivity between 50 ohm-cm and 110 ohm-cm at 25° C., and between 20 ohm-cm and 50 ohm-cm at 150° C., and between 150,000 ohm-cm and 325,000 ohm-cm at 280° C. In an embodiment, the PTCR heating element has a resistivity between 50 ohm-cm and 150 ohm-cm at 25° C., and between 20 ohm-cm and 100 ohm-cm at 150° C., and between 150,000 ohm-cm and 350,000 ohm-cm at 280° C.In an embodiment, the PTCR heating element has a resistivity between 50 ohm-cm and 200 ohm-cm at 25° C., and between 20 ohm-cm and 150 ohm-cm at 150° C., and between 150,000 ohm-cm and 375,000 ohm-cm at 280° C. In an embodiment, the PTCR heating element has a resistivity between 50 ohm-cm and 300 ohm-cm at 25° C., and between 20 ohm-cm and 200 ohm-cm at 150° C., and between 150,000 ohm-cm and 400,000 ohm-cm at 280° C. In an embodiment, the PTCR heating element has a resistivity between 50 ohm-cm and 400 ohm-cm at 25° C., and between 20 ohm-cm and 250 ohm-cm at 150° C., and between 150,000 ohm-cm and 450,000 ohm-cm at 280° C. In an embodiment, the PTCR heating element has a resistivity between 50 ohm-cm and 500 ohm-cm at 25° C., and between 20 ohm-cm and 300 ohm-cm at 150° C., and between 150,000 ohm-cm and 500,000 ohm-cm at 280° C. In an embodiment, the PTCR heating element has a resistivity between 90 ohm-cm and 110 ohm-cm at 25° C., and between 30 ohm-cm and 50 ohm-cm at 150° C., and between 200,000 ohm-cm and 325,000 ohm-cm at 280° C. In an embodiment, the PTCR heating element has a resistivity between 90 ohm-cm and 150 ohm-cm at 25° C., and between 30 ohm-cm and 100 ohm-cm at 150° C., and between 200,000 ohm-cm and 350,000 ohm-cm at 280° C. In an embodiment, the PTCR heating element has a resistivity between 90 ohm-cm and 200 ohm-cm at 25° C., a resistivity between 30 ohm-cm and 150 ohm-cm at 150° C., and a resistivity between 200,000 ohm-cm and 375,000 ohm-cm at 280° C. In an embodiment, the PTCR heating element has a resistivity between 90 ohm-cm and 300 ohm-cm at 25° C., a resistivity between 30 ohm-cm and 200 ohm-cm at 150° C., and a resistivity between 200,000 ohm-cm and 400,000 ohm-cm at 280° C.In an embodiment, the PTCR heating element has a resistivity between 90 ohm-cm and 400 ohm-cm at 25° C., and between 30 ohm-cm and 250 ohm-cm at 150° C., and between 200,000 ohm-cm and 450,000 ohm-cm at 280° C. In an embodiment, the PTCR heating element has a resistivity between 90 ohm-cm and 500 ohm-cm at 25° C., and between 30 ohm-cm and 300 ohm-cm at 150° C., and between 200,000 ohm-cm and 500,000 ohm-cm at 280° C. In an embodiment, the PTCR heating element has a resistivity between 10 ohm-cm and 110 ohm-cm at 50° C., and between 10 ohm-cm and 110 ohm-cm at 100° C., and between 50,000 ohm-cm and 125,000 ohm-cm at 260° C. In an embodiment, the PTCR heating element has a resistivity between 10 ohm-cm and 150 ohm-cm at 50° C., and between 10 ohm-cm and 150 ohm-cm at 100° C., and between 50,000 ohm-cm and 150,000 ohm-cm at 260° C. In an embodiment, the PTCR heating element has a resistivity between 10 ohm-cm and 200 ohm-cm at 50° C., and between 10 ohm-cm and 200 ohm-cm at 100° C., and between 50,000 ohm-cm and 175,000 ohm-cm at 260° C. In an embodiment, the PTCR heating element has a resistivity between 10 ohm-cm and 300 ohm-cm at 50° C., and between 10 ohm-cm and 300 ohm-cm at 100° C., and between 50,000 ohm-cm and 200,000 ohm-cm at 260° C. In an embodiment, the PTCR heating element has a resistivity between 10 ohm-cm and 400 ohm-cm at 50° C., and between 10 ohm-cm and 400 ohm-cm at 100° C., and between 50,000 ohm-cm and 250,000 ohm-cm at 260° C. In an embodiment, the PTCR heating element has a resistivity between 10 ohm-cm and 500 ohm-cm at 50° C., and between 10 ohm-cm and 500 ohm-cm at 100° C., and between 50,000 ohm-cm and 300,000 ohm-cm at 260° C.In an embodiment, the PTCR heating element has a resistivity between 50 ohm-cm and 110 ohm-cm at 50° C., and between 50 ohm-cm and 110 ohm-cm at 100° C., and between 75,000 ohm-cm and 125,000 ohm-cm at 260° C. In an embodiment, the PTCR heating element has a resistivity between 50 ohm-cm and 150 ohm-cm at 50° C., and between 50 ohm-cm and 150 ohm-cm at 100° C., and between 75,000 ohm-cm and 150,000 ohm-cm at 260° C. In an embodiment, the PTCR heating element has a resistivity between 50 ohm-cm and 200 ohm-cm at 50° C., and between 50 ohm-cm and 200 ohm-cm at 100° C., and between 75,000 ohm-cm and 175,000 ohm-cm at 260° C. In an embodiment, the PTCR heating element has a resistivity between 50 ohm-cm and 300 ohm-cm at 50° C., and between 50 ohm-cm and 300 ohm-cm at 100° C., and between 75,000 ohm-cm and 200,000 ohm-cm at 260° C. In an embodiment, the PTCR heating element has a resistivity between 50 ohm-cm and 400 ohm-cm at 50° C., and between 50 ohm-cm and 400 ohm-cm at 100° C., and between 75,000 ohm-cm and 250,000 ohm-cm at 260° C. In an embodiment, the PTCR heating element has a resistivity between 50 ohm-cm and 500 ohm-cm at 50° C., and between 50 ohm-cm and 500 ohm-cm at 100° C., and between 75,000 ohm-cm and 300,000 ohm-cm at 260° C. In an embodiment, the PTCR heating element has a resistivity between 75 ohm-cm and 110 ohm-cm at 50° C., and between 90 ohm-cm and 110 ohm-cm at 100° C., and between 100,000 ohm-cm and 125,000 ohm-cm at 260° C. In an embodiment, the PTCR heating element has a resistivity between 75 ohm-cm and 150 ohm-cm at 50° C., and between 90 ohm-cm and 150 ohm-cm at 100° C., and between 100,000 ohm-cm and 150,000 ohm-cm at 260° C.In an embodiment, the PTCR heating element has a resistivity between 75 ohm-cm and 200 ohm-cm at 50° C., and between 90 ohm-cm and 200 ohm-cm at 100° C., and between 100,000 ohm-cm and 175,000 ohm-cm at 260° C. In an embodiment, the PTCR heating element has a resistivity between 75 ohm-cm and 300 ohm-cm at 50° C., and between 90 ohm-cm and 300 ohm-cm at 100° C., and between 100,000 ohm-cm and 200,000 ohm-cm at 260° C. In an embodiment, the PTCR heating element has a resistivity between 75 ohm-cm and 400 ohm-cm at 50° C., and between 90 ohm-cm and 400 ohm-cm at 100° C., and between 100,000 ohm-cm and 250,000 ohm-cm at 260° C. In an embodiment, the PTCR heating element has a resistivity between 75 ohm-cm and 500 ohm-cm at 50° C., and between 90 ohm-cm and 500 ohm-cm at 100° C., and between 100,000 ohm-cm and 300,000 ohm-cm at 260° C.

[0101] Fig.11 Another exemplary PTCR resistivity versus temperature curve is shown. In this example, the density of the PTCR material is 5700 kg / m 3 , heat capacity of 520 J / kg K, and thermal conductivity of 2.1 W / m K. The resistivity begins to increase at a temperature after about 440 K, and then increases sharply between 503 K and 518 K. At 298 K, the resistivity of the PTCR material forming the PTCR heating element is 0.168 ohm-m, while at 373 K, the resistivity of the PTCR material forming the PTCR heating element is 0.105 ohm-m, and at 518 K, the resistivity of the PTCR material forming the PTCR heating element is 3.669 ohm-m. In some exemplary embodiments, the PTCR material has a thermal conductivity of 5000 kg / m 3 and 7000kg / m 3 , a heat capacity between 450 J / kg K and 600 J / kg K, and a thermal conductivity between 1.5 W / m K and 3.0 W / m K.

[0102] Fig. 12A FIG. 5 is a diagram illustrating an exemplary PTCR heating element 50 that can achieve improved evaporator heating. A thin section of nonlinear PTCR material 10 is shown in FIG. Fig. 12A , in which the nonlinear PTCR material 10 is sandwiched between conductive layers 20, which in turn are attached to conductive leads 30, such that the conductive leads 30 can have a differential voltage applied thereto. Fig. 12B yes Fig. 12A A cross section of an exemplary PTCR heating element 50 is shown in FIG.

[0103] In some exemplary embodiments, the PTCR heater 50 includes Fig. 12A The illustrated geometry, with a nonlinear PTCR material thickness of 0.5 mm (height) and 5.0 mm in the other dimensions (length and width), is effective in an evaporator device using, for example, a combined fluid comprising propylene glycol and glycerol. The electrical properties of the nonlinear PTCR material include these values: T1 value between 150°C and 300°C, such as between 220°C and 280°C; resistivity at temperatures below T1 between 0.01 Ohm-m and 100 Ohm-m, such as between 0.1 Ohm-m and 1 Ohm-m; the resistivity change between T1 and T2 has an increase factor of more than 10, such as more than 100; and the temperature difference between T1 and T2 is less than 200°C, such as less than 50°C.

[0104] FIG. 13A to FIG. 13E Modeled temperatures for an exemplary PTCR heater 50 are shown. In the example shown, the nonlinear PTCR material 10 includes a flat plate geometry with dimensions of 5 mm×5 mm×0.5 mm; the conductive layer 20 is formed of silver (Ag) with dimensions of 5 mm×5 mm×0.025 mm; and the conductive lead 30 is formed of copper (CU) with dimensions of 12 mm×2 mm×0.2 mm. The nonlinear PTCR material 10 includes a Fig.32 The PTCR resistivity versus temperature curve shown has a non-linear transition region from about 240° C. to about 300° C. A voltage of 3 to 6 volts is applied across the conductive leads 30 of the exemplary PTCR heater 50. Under these conditions, the temperature of the exemplary PTCR heater 50 in open air with free convection airflow will increase as FIG. 13A to FIG. 13E The modeling series of FIG. 1 and FIG. 2 respectively illustrate 0.0, 0.2, 0.5, 1.0 and 2.0 seconds after the differential voltage is applied. As shown, the temperature is relatively uniform over 1.0 second, and the peak temperature at the surface of the conductive layer 20 is less than 270°C.

[0105] FIG. 14A to FIG. 14FModeled temperatures for another example of a PTCR heater 50 are shown. A gradient temperature scale is shown on the left side of each figure, with red representing the hottest temperature of approximately 255°C and sequentially through the colors of the visible spectrum (i.e., red, orange, yellow, green, blue, and violet) to a coldest temperature of approximately 23°C. In each of the examples shown, the nonlinear PTCR material 10 includes a flat plate geometry having dimensions of approximately 5 mm×5 mm×0.5 mm; the conductive layer 20 is formed of silver (Ag) having dimensions of approximately 5 mm×5 mm×0.025 mm; and the conductive lead 30 is formed of copper (CU) having dimensions of approximately 12 mm×2 mm×0.2 mm. The flat plate geometry may include two parallel sides including the conductive layer 20 to which the conductive lead 30 is attached. The conductive lead 30 is centrally attached to the conductive layer 20 on each side of the PTCR heating element 50 by a connector 40. In an embodiment, the connector 40 is a clamp, a clip, a conductive paste, a high temperature, a lead-free solder, and / or a combination thereof.

[0106] Fig.14A The temperature is shown 1.0 second after activation by applying current to the PTCR heating element 50. The purple conductive lead 30 is still approximately 25° C. The temperature of most of the PTCR material 10 and conductive layer 20 has risen to approximately 120° C., with the area in the center including the connector 40 being slightly cooler at a temperature of approximately 80° C.

[0107] Fig. 14B The temperature is shown 2.0 seconds after activation by applying current to the PTCR heating element 50. The temperature of the blue / green conductive lead 30 has increased to about 90° C. The temperature of most of the PTCR material 10 and conductive layer 20 has increased to about 210° C., with the area in the center including the connector 40 being cooler at a temperature of about 160° C.

[0108] Fig. 14C The temperature is shown 3.0 seconds after activation by applying current to the PTCR heating element 50. The temperature of the green conductive lead 30 has increased to about 140° C. The temperature of most of the PTCR material 10 and conductive layer 20 has increased to about 250° C., with the area in the center including the connector 40 being cooler at a temperature of about 200° C.

[0109] Fig.14D The temperature is shown 4.0 seconds after activation by applying current to the PTCR heating element 50. The temperature of the green conductive lead 30 has increased to about 160° C. Most of the PTCR material 10 and conductive layer 20 remain at about 250° C., with the area in the center including the connector 40 being cooler at a temperature of about 215° C.

[0110] Fig.14EThe temperature is shown 5.0 seconds after activation by applying current to the PTCR heater 50. The temperature of the green / yellow conductive lead 30 has increased to about 180° C. Most of the PTCR material 10 and conductive layer 20 remain at a temperature of about 250° C., with the area in the center including the connector 40 being cooler at a temperature of about 225° C.

[0111] Fig.14F The temperature is shown 6.0 seconds after activation by applying current to the PTCR heating element 50. The temperature of the yellow conductive lead 30 has increased to about 200° C. Most of the PTCR material 10 and conductive layer 20 remain at a temperature of about 250° C., with the area in the center including the connector 40 being just slightly cooler at a temperature of about 235° C. Fig.15 The modeled temperature of an exemplary heater is shown after voltage is applied for 6.0 seconds under free convection conditions.

[0112] Fig.16A Modeled surface temperature of an exemplary PTCR heating element as a function of time is shown. In the model, the surface temperature of the PTCR heater starts at 25°C (i.e., room temperature) at time zero. After the current is applied, the surface temperature rises linearly for about 2 seconds to a temperature of about 225°C. After about 2 seconds, the rate of temperature increase gradually decreases to a steady-state operating temperature of about 250°C, which is reached about 3 seconds after activation. In the model, the nonlinear PTCR material is assumed to be in a non-contact, free convection state, and the emitted radiation is measured from a certain distance. In an embodiment, the PTCR heating element is heated to an operating temperature between 240°C and 280°C. In an embodiment, the PTCR heating element is heated to an operating temperature between 245°C and 255°C. In an embodiment, the PTCR heating element is heated to an operating temperature of about 250°C.

[0113] Fig. 16BModeled and measured maximum surface temperature as a function of time for an exemplary PTCR heater are illustrated. Four measurements were repeated using an infrared camera to measure the maximum surface temperature of the PTCR heater as a function of time, which was then plotted against the model of the maximum surface temperature. In the model, the nonlinear PTCR material is assumed to be in a non-contact, free convection state, and the emitted radiation is measured at a distance. In each case, the maximum surface temperature of the PTCR heating element starts at about 25°C (i.e., room temperature) at time zero. After the current is applied, the maximum surface temperature rises linearly for about 2 seconds to reach a temperature of about 225°C. After about 2 seconds, the rate of temperature increase gradually decreases to reach a steady-state operating temperature of about 250°C, which is reached about 3 seconds after activation. In an embodiment, the PTCR heating element is heated to an operating temperature between 240°C and 280°C. In an embodiment, the PTCR heating element is heated to an operating temperature between 245°C and 255°C. In an embodiment, the PTCR heating element is heated to an operating temperature of about 250°C.

[0114] Fig. 16C Modeled and measured average surface temperature as a function of time for an exemplary PTCR heating element are illustrated. Four measurements were repeated using an infrared camera to measure the average surface temperature of the PTCR heating element as a function of time, which was then modeled and plotted relative to the average surface temperature. In the model, the nonlinear PTCR material is assumed to be in a non-contact, free convection state, and the emitted radiation is measured at a certain distance. In each case, the average surface temperature of the PTCR heating element starts at about 25°C (i.e., room temperature) at time zero. After the current is applied, the maximum surface temperature rises linearly for about 2 seconds, reaching a temperature of about 225°C. After about 2 seconds, the rate of temperature increase gradually decreases to a steady-state operating temperature of about 250°C, which is reached about 3 seconds after activation. In an embodiment, the PTCR heating element is heated to an operating temperature between 240°C and 280°C. In an embodiment, the PTCR heating element is heated to an operating temperature between 245°C and 255°C. In an embodiment, the PTCR heating element is heated to an operating temperature of about 250°C.

[0115] Fig.17 The transient current response as a function of time of an exemplary heater consistent with an embodiment of the current subject matter is shown. In the figure, the current is measured in amperes, which increases at a nearly linear rate and reaches a peak consumption after about 1.5 seconds from activation. Thereafter, as the PTCR heater reaches a self-regulating operating temperature, the resistance increases rapidly to reduce the current consumption.

[0116] Uniform temperature can be a desirable property of a PTCR heater, providing a distinct advantage over series coil heaters that include series heaters with power input controlled by a temperature sensor, electronic circuitry with a microprocessor, and complex algorithms dedicated to temperature control purposes. These existing series heaters can have total power modulated in response to a temperature measurement at a certain point or an average temperature estimated by total resistivity combined with the TCR (temperature coefficient of resistivity) of a typical series heating element. However, in some series heaters, the temperature within the series heater can vary by 40°C or more because of local differences in the thermal mass of the surrounding dielectric, as well as local differences in the loss of the probe dielectric, resulting in local resistivity variations along the series heater.

[0117] In some embodiments, the PTCR heater 50 is composed of Fig. 9 The same or similar nonlinear PTCR resistivity versus temperature curves as shown in the drawings may be formed of materials having, for example, FIG. 12A to FIG. 12B With the parallel geometry shown, and with sufficient (e.g., 3V to 6V) differential voltage applied to the conductive leads 30, each given control volume within such a PTCR heater will have a temperature within a narrow range, typically less than 10°C. This can be achieved even with differential heat loads. By controlling the material and geometric arrangement of the PTCR heating elements, a range of less than 10°C can be tailored for evaporation.

[0118] Alternative PTCR heater designs and geometries are possible.

[0119] In an embodiment, the PTCR heater may include a heat exchanger for preheating air entering and passing through the vaporizable material. Fig.18 is a perspective view of an exemplary PTCR heater assembly 395 including a PTCR heater 390 and a heat exchanger element 320 that enables convective heating and improved uniform heating of the vaporizable material.

[0120] An exemplary PTCR heater assembly 395 (also referred to as a rectangular PTCR air heater assembly) includes a PTCR heater 390 that includes a PTCR material 300 sandwiched between conductive layers 305. In contact with the conductive layers 305 is a heat exchanger element 320, which can be made of, for example, aluminum or other thermally conductive materials. The heat exchanger element 320 can be extruded or assembled from a thermally conductive material. In an embodiment, the heat exchanger element 320 can be a foamed metal, such as foamed aluminum. The heat exchanger element 320 can be made by extrusion, machining, milling, casting, foaming, printing, injection molding, forging, stamping, sintering, and other metal forming methods. Surrounding the heat exchanger element 320 is a heater assembly cover 350. In an embodiment, the heater assembly cover 350 includes a non-conductive material. In an embodiment, the heater assembly cover 350 includes a non-conductive material. In an embodiment, the heater assembly cover 350 includes a metal having a non-conductive coating that isolates the heater assembly cover 350 from the heat exchanger element 320. In an embodiment, the heater assembly cover 350 comprises polytetrafluoroethylene (PTFE).

[0121] Fig.19 398 is an exploded view of a PTCR evaporation assembly 398, including an exploded view of an exemplary PTCR heater assembly 395. In some embodiments, the PTCR evaporation assembly 398 is rectangular. The PTCR evaporation assembly 398 includes an exemplary PTCR heater assembly 395 and a product cover 380 for accommodating a disposable product 360. In some embodiments, the product cover 380 and the disposable product 360 are both rectangular. In an embodiment, the disposable product 360 in the product cover 380 may include a disposable product containing a solid vaporizable material. In an embodiment, the product cover 380 is a disposable liquid cartridge (e.g., a pod) configured to accommodate a liquid vaporizable material. In an embodiment, the product cover 380 is a disposable liquid cartridge (e.g., a pod) comprising a first air inlet and / or a wick, and is configured to accommodate a liquid vaporizable material.

[0122] Fig. 20 is a perspective view of an assembled exemplary PTCR vaporization assembly 398. The product cover 380 containing the disposable product therein can be attached to the heater assembly cover 350, the PTCR heater assembly, and / or the adjacent portion on the opposite side of the product cover 380 by interference fit, press fit, snap fit coupling, magnetic coupling, adhesive, or other fastening means. The product cover 380 can be releasably attached so that it can be separated from the vaporizer device to replace the disposable product and then reassembled.

[0123] Fig.21is a perspective view of an exemplary PTCR vaporization assembly 398 and disposable product 360. In an embodiment, the disposable product 360 and product cover 380 may include a disposable product containing a solid vaporizable material. In an embodiment, the disposable product 360 and product cover 380 may include a disposable liquid cartridge (e.g., pod) containing a liquid vaporizable material. In an embodiment, the disposable product 360 and product cover 380 may include a disposable liquid cartridge (e.g., pod) having a first air inlet and / or a wick, and containing a liquid vaporizable material. Although Fig.21 The PTCR heater is not shown in the figure, but is inserted in the volume 304 between the heat exchanger elements 320. The heat exchanger elements 320 provide increased surface area for heating more incoming air than if only the PTCR heater (without the heat exchanger) were used to heat the incoming air. Surrounding the heat exchanger elements 320 is a heater assembly cover 350. In an embodiment, the flow rate of incoming air through the PTCR heater assembly 395 is approximately 1.4 liters per minute. The heat exchanger elements 320 can reach a steady state temperature in excess of 200°C to quickly heat the incoming air. The heat exchanger elements 320 can be designed to have a specific surface area (mm 2 / mm 3 ) is maximized, which provides improved heat transfer from the PTCR heater to the heat exchanger element 320, and also provides improved heat transfer from the heat exchanger element 320 to the incoming air. Fig.21 As shown, the heat exchanger element 320 may be a fin design made of a thermally conductive material (eg, a metal such as aluminum, copper, steel, stainless steel, titanium).

[0124] Fig. 22 398 and disposable product 360 after the PTCR heater 390 is activated for about 0.2 seconds. The PTCR heater 390 heats the heat exchanger element 320, which transfers heat to the air entering the PTCR heater assembly 395. The air leaving the PTCR heater assembly 395 has been heated to a temperature between about 110°C and about 160°C. The heated airflow flows through the disposable product 360 (e.g., a tobacco-containing medium) at a flow rate of about 1.4 liters per minute. The vapor and / or aerosol leaving the PTCR vaporization assembly 398 contains vaporized material released from the disposable product 360 at a temperature between about 50°C and about 150°C.

[0125] Fig.23398 and disposable product 360 after activation of PTCR heater 390 for about 0.5 seconds. PTCR heater 390 heats heat exchanger element 320, which transfers heat to air entering PTCR heater assembly 395. Air leaving PTCR heater assembly 395 has been heated to a temperature between about 150°C and about 210°C. The heated airflow flows through disposable product 360 (e.g., tobacco-containing medium) at a flow rate of about 1.4 liters per minute. The vapor and / or aerosol leaving PTCR vaporization assembly 398 contains vaporized material released from disposable product 360 at a temperature between about 100°C and about 210°C.

[0126] Fig.24 398 and disposable product 360 after activation of PTCR heater 390 for about 1.0 seconds. PTCR heater 390 heats heat exchanger element 320, which transfers heat to air entering PTCR heater assembly 395. Air leaving PTCR heater assembly 395 has been heated to a temperature between about 170°C and about 230°C. The heated airflow flows through disposable product 360 (e.g., tobacco-containing medium) at a flow rate of about 1.4 liters per minute. The vapor and / or aerosol leaving PTCR vaporization assembly 398 contains vaporized material released from disposable product 360 at a temperature between about 110°C and about 220°C.

[0127] Fig.25 398 and disposable product 360 after the PTCR heater 390 is activated for about 2.0 seconds. The PTCR heater 390 heats the heat exchanger element 320, which transfers heat to the air entering the PTCR heater assembly 395. The air leaving the PTCR heater assembly 395 has been heated to a temperature between about 180°C and about 240°C. The heated airflow flows through the disposable product 360 (e.g., a tobacco-containing medium) at a flow rate of about 1.4 liters per minute. The vapor and / or aerosol leaving the PTCR vaporization assembly 398 contains vaporized material released from the disposable product 360 at a temperature between about 120°C and about 230°C.

[0128] Fig.263.0 seconds after the activation of the PTCR heater 390, an exemplary PTCR vaporization assembly 398 and a disposable product 360. The PTCR heater 390 heats the heat exchanger element 320, which transfers heat to the air entering the PTCR heater assembly 395. The air leaving the PTCR heater assembly 395 has been heated to a temperature between about 180°C and about 240°C. The heated airflow flows through the disposable product 360 (e.g., a tobacco-containing medium) at a flow rate of about 1.4 liters per minute. The vapor and / or aerosol leaving the PTCR vaporization assembly 398 contains vaporized material released from the disposable product 360 at a temperature between about 120°C and about 230°C.

[0129] The current subject matter is not limited to rectangular geometries. In embodiments, the PTCR heater is a polygon that is not a rectangle. For example, alternative designs of PTCR heaters may differ from planar geometries in many configurations produced by extrusion or injection molding. For example, Fig. 27 is a perspective view of an exemplary PTCR heater 290 having a cylindrical geometry. In this example, the PTCR heater 290 includes a PTCR material 200 having surface conductive layers 205, each of which is cylindrical.

[0130] Fig.28 is an exploded view showing an exemplary PTCR heater assembly 295, which includes an exemplary PTCR heater 290, an external heat exchanger 210, an internal heat exchanger 220, a flow divider 230, and a heater assembly cover 250, each of which is cylindrical. Fig.29 is a perspective view of an exemplary PTCR heater assembly 295 . Fig.30 is a perspective view of an exemplary PTCR evaporation assembly 298 with the outer cover and diverter 230 removed, showing the orientation of the PTCR heater 290 , the external heat exchanger 210 , and the internal heat exchanger 220 in alignment with the disposable product 260 .

[0131] Fig.31 is a perspective view of an exemplary PTCR evaporation assembly 298, which includes a PTCR heater 290, an external heat exchanger 210, an internal heat exchanger 220, a diverter 230, a heater assembly cover 250, and a product cover 280 (in FIG. Fig.18 In the example, the product cover covers the disposable product 260).

[0132] Fig.32 is a graph of the logarithm of resistivity as a function of temperature for an exemplary evaporation device having a PTCR heater. Fig.32The performance shown is based on example calculations that characterize the performance of an exemplary embodiment of a cylindrical PTCR evaporation assembly 298. The exemplary PTCR evaporation assembly 298 is a HNB device in which a solid vaporizable material (e.g., HNB product) is treated as a porous medium in the calculation as a disposable product 260, with a mass specific surface area ratio. density Convective heat transfer constant The volume specific surface area can be calculated as S vol =S m xρ=10000cm 2 / gΔ1000g / kgΔm 2 / 10000cm 2 ,and The volumetric heat transfer coefficient is obtained from

[0133] For the above calculations, the ambient conditions were a standard pressure of 1 atmosphere and a temperature of 20.05°C. The input airflow rate was constant at 1.4 l / m and the voltage applied across the opposing conductive layers 205 was constant at 3.7 volts. Fig.32 Outside of the PTCR behavior shown, no current limiting is applied.

[0134] The calculated evaporation device with PTCR heater includes a conductive layer 205 of silver, a cylindrical external heat exchanger 210 and a cylindrical internal heat exchanger 220 which are aluminum extrusions, a diverter 230 and a heater assembly cover 250 made of PTFE, and a product cover 280 made of paper.

[0135] Fig.33 is a cross-sectional view showing a temperature simulation of an exemplary embodiment of a PTCR evaporation assembly 298, which is also described above in conjunction with Fig.32 The PTCR evaporation assembly 298 includes a PTCR heater assembly 295 for heating a disposable product (eg, solid evaporation material) 260 . FIG. 34A to FIG. 34G is a cutaway diagram showing the transient response of temperature as color for an exemplary embodiment of a PTCR evaporation assembly 298 with a PTCR heater assembly 295 . FIG. 34A to FIG. 34G It shows that the temperature will not exceed 280℃ anywhere, which is much lower than the combustion temperature of 260℃ for disposable products. FIG. 34A to FIG. 34G As can be seen in FIG. 1 , the heating of the disposable product (eg, solid vaporizable material) 260 is performed in a wave-like manner from upstream to downstream, thereby eliminating cross-sectional hot spots and the resulting voids of different porosities.

[0136] In the above description and claims, phrases such as "at least one" or "one or more" may appear after the conjunction enumeration of elements or features. The term "and / or" may also appear in the enumeration of two or more elements or features. Unless otherwise implicitly or explicitly contradictory to the context used, the phrase is intended to mean any of the listed elements or features individually or any combination of the listed elements or features with other listed elements or features. For example, the phrases "at least one of A and B", "one or more of A and B" and "A and / or B" are each intended to mean "A alone, B alone, or A and B together". There is also a similar explanation for the enumeration of three or more items. For example, the phrases "at least one of A, B and C", "one or more of A, B and C", "A, B and / or C" are each intended to mean "A alone, B alone, C alone, A and B together, A and C together, B and C together, or A and B and C together". In addition, the term "based on" used above and in the claims is intended to mean "based at least in part", so that unlisted features or elements are also allowed.

[0137] The subject matter described herein may be embodied in systems, devices, methods and / or articles, depending on the desired configuration. The embodiments listed in the above description do not represent all embodiments consistent with the subject matter described herein. Instead, they are just some examples consistent with the relevant aspects of the subject matter. Although some variations have been described in detail above, other modifications or additions may be made. In particular, in addition to the features and / or changes listed herein, further features and / or changes may be provided. For example, the embodiments described above may be directed to various combinations and subcombinations of the disclosed features and / or combinations and subcombinations of several further features disclosed above. In addition, the logic flows described in the accompanying drawings and / or the logic flows described herein do not necessarily require the specific order or sequential order shown to achieve the desired results. Other embodiments may be within the scope of the following claims.

Claims

1. An evaporator device, comprising: a housing including an air inlet; a heating element within the housing, the heating element comprising a non-linear positive temperature coefficient of resistivity material, wherein the non-linear positive temperature coefficient of resistivity material comprises a resistivity transition region in which the resistivity increases over a temperature range such that when the heating element is heated to above a first temperature within the resistivity transition region, current from a power source is reduced to a level that limits further temperature increase of the heating element; as well as a heat exchanger thermally coupled to the heating element and arranged to receive the airflow from the air inlet, the heat exchanger being configured to transfer heat between the heating element and the airflow to produce a heated airflow, wherein the heated airflow exiting the heat exchanger is configured to vaporize a vaporizable material, wherein the heat exchanger is made of foamed metal. 2 . The evaporator device of claim 1 , wherein the heat exchanger comprises a first heat exchanger thermally coupled to a first side of the heating element, the heat exchanger comprises a second heat exchanger thermally coupled to a second side of the heating element.

3. The evaporator device of any one of claims 1 to 2, wherein the heat exchanger comprises a plurality of fin features.

4. The evaporator device according to any one of claims 1 to 3, wherein the heat exchanger is made of aluminum, copper, steel or titanium.

5. The evaporator device according to any one of claims 1 to 4, wherein the heat exchanger is extruded from a thermally conductive material.

6. The evaporator device of claim 1, wherein the foamed metal is foamed aluminum.

7. The evaporator device according to any one of claims 1 to 2, further comprising: A flow splitter is located in the airflow path and is configured to split a portion of the airflow through the heat exchanger.

8. The evaporator device of any one of claims 1 to 2, wherein the housing includes a heater assembly cover that houses the heat exchanger.

9. The evaporator device according to any one of claims 1 to 2, further comprising: A power source is configured to provide electrical energy to the heating element.

10. The evaporator device according to any one of claims 1 to 2, further comprising: Product cover to contain vaporizable material.

11. The evaporator device according to any one of claims 1 to 2, wherein the vaporizable material is a solid vaporizable material.

12. The vaporizer device of claim 10, wherein the product cover comprises a cartridge having a first air inlet.

13. The vaporizer device of claim 12, wherein the housing includes a connector configured to couple the housing to the cartridge containing the vaporizable material.

14. The evaporator device of claim 13, wherein the cartridge contains a solid vaporizable material.

15. The vaporizer device of claim 12, wherein the cartridge comprises a reservoir, a liquid vaporizable material within the reservoir, and a wick in fluid communication with the liquid vaporizable material, wherein the cartridge is configured to receive a heated air flow through the first air inlet and direct the heated air flow through the wick.

16. The vaporizer device of claim 15, wherein the cartridge includes a nozzle and the wick is located in the path of the heated air flow between the heating element and the nozzle.

17. The evaporator device of claim 12, wherein the cartridge comprises a second air inlet configured to draw a second air flow into the cartridge to mix with the heated air flow.

18. An evaporator device according to claim 17, wherein the second air inlet is located in a nozzle of the cartridge.

19. The vaporizer device of claim 13, wherein the cartridge comprises: a reservoir containing a vaporizable material, wherein the vaporizable material is a liquid vaporizable material; a wick in fluid communication with the liquid vaporizable material, the wick being arranged to receive a heated gas flow from a heat exchanger to vaporize the vaporizable material to produce a vapor and / or a first aerosol; a solid vaporizable material arranged to receive the vapor and / or the first aerosol to produce a second aerosol; as well as A mouthpiece is configured to receive the second aerosol after the vapor and / or the first aerosol has passed through the solid vaporizable material.

20. An evaporator device comprising: a housing including an air inlet; a heating element within the housing, the heating element comprising a non-linear positive temperature coefficient of resistivity material; a heat exchanger thermally coupled to the heating element and arranged to receive the airflow from the air inlet, the heat exchanger configured to transfer heat between the heating element and the airflow to produce a heated airflow, wherein the heated airflow exiting the heat exchanger is configured to vaporize a vaporizable material; A product cover containing the vaporizable material, wherein the product cover comprises a cartridge having a first air inlet and a wick in fluid communication with the vaporizable material, the cartridge being configured to receive a heated airflow through the first air inlet and direct the heated airflow through the wick.

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