On-demand portable counterflow evaporator

Abstract

A demand on-hand portable vaporizer that operates primarily by convection. The vaporizer is configured to allow very rapid (e.g., within seconds) heating of air drawn through an oven chamber to a predetermined or selectable vaporization temperature to vaporize material (e.g., loose leaf plant material, etc.) held in the oven chamber. The vaporizer provides efficient transfer of heated air and rapid delivery of vaporizable material to the user.

Description

[0001] This application is a divisional application of patent application filed on June 16, 2017, with application number 201780050037.7 (international application number PCT / US2017 / 038014) and entitled "Portable Convection Evaporator on Demand". Cross-reference to related applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 62 / 351,272, filed June 16, 2016, entitled “Electronic Vaporizer Devices,” and U.S. Provisional Patent Application No. 62 / 441,090, filed December 30, 2016, entitled “On-Demand Portable Convection Vaporizers,” the disclosures of which are incorporated herein by reference in their entirety. Background Technology

[0003] Evaporation devices, including electronic vaporizers or electronic vaporizer devices, allow the delivery of vapors containing one or more active ingredients via inhalation. Electronic vaporizer devices are increasingly popular for delivering pharmaceuticals for prescribed medical purposes and for consumer tobacco and other plant-based extractable materials, including solid (e.g., leaf-like) materials, solid / liquid (e.g., suspensions, liquid coatings) materials, wax extracts, and pre-filled pods (cores, packaged containers, etc.). Electronic vaporizer devices are particularly portable, stand-alone, and easy to use. Typically, such devices are controlled by one or more switches, buttons, or the like (control devices) on the vaporizer, although several devices that can communicate wirelessly with external controllers (e.g., smartphones) have recently become available.

[0004] Evaporation by applying heat can be performed through convection, conduction, radiation, and / or other means, including various combinations of these methods. While evaporators that primarily apply heat via convection (so-called convection-based evaporators) have been described, they are generally slower and therefore less convenient than other evaporators, such as those using conduction or primarily using conduction. In particular, providing a portable / handheld convection-based evaporator sufficient to allow the evaporable material to evaporate immediately or nearly immediately (e.g., in seconds or less) as the user draws the evaporator in. Currently available commercially available portable convection-based evaporators do not offer this on-demand heating and evaporation. Typically, portable convection-based evaporators require a certain amount of heating time for the device to properly evaporate the material of interest, which may be long enough to frequently inconvenience the user and may also require further cooling time.

[0005] For example, the previously described convection-based portable evaporators require some form of physical selection input from the user to turn the device on or off. This is typically done via some form of mechanical switch or button; once the device is on, it requires a certain amount of time (approximately tens of seconds or minutes) to reach the appropriate evaporation temperature before the user can effectively use the device to actively draw steam. With such convection-based portable evaporators, due to, for example, relatively long periods of unused preheating and cooling at high temperatures and the internal characteristics of the evaporator, some portion of any active component of the evaporable material may be lost into the surrounding environment (and thus unavailable to the user). Furthermore, such convection-based evaporators may not be able to precisely control the temperature of the air in contact with the material. The lack of air temperature control, along with variations in airflow rate caused by the user, can lead to significant variations in the quality and quantity of the generated steam. In particular, many so-called on-demand or “instant-heating” evaporators suffer from this problem: although the heating element may heat up very quickly, the airflow may not be heated sufficiently and / or uniformly. This may be at least partly due to the large thermal mass surrounding the heater, and the wasted energy dissipated into the device rather than circulating air. This could result in users having to perform multiple "sucking" operations or wait for an extended period of time before the device can produce a sufficient amount of high-quality steam to their satisfaction. Summary of the Invention

[0006] An aspect of the subject matter of this invention relates to an on-demand portable convection evaporator device that provides efficient transfer of heated air and rapid delivery of evaporable materials to the user.

[0007] An evaporator consistent with certain embodiments of the present subject includes an evaporator body having an outer shell; a heater located within the evaporator body having at least one opening through which air is passed and heated; an oven chamber containing an evaporable material, the oven chamber being configured to be heated by air heated by the heater, such that the evaporable material evaporates at least partially into the heated air; a controller coupled to the heater and configured to heat the heater to a certain temperature; and a suction nozzle configured to deliver the heated air and the evaporated material.

[0008] An evaporator consistent with certain embodiments of the present subject includes an evaporator body having an outer shell and an internal structural shell housed within the outer shell and defining a cavity; an air inlet extending through a portion of the outer shell and into the cavity of the internal structural shell, through which air enters the cavity; a heater suspended within the cavity of the internal structural shell, the heater having one or more openings through which air passes, the heater and the openings generating turbulence in the air as it passes through and is heated by the heater; an oven chamber located within the cavity of the internal structural shell, in which an evaporable material is held, the oven chamber being configured to be heated by air heated by the heater, thereby causing the evaporable material to evaporate into the heated air; a controller coupled to the heater and configured to heat the heater to a predetermined temperature upon detecting airflow arriving at the heater; and a nozzle configured to deliver the heated air and the evaporated material.

[0009] Methods consistent with certain embodiments of the present subject include sensing suction at the evaporator nozzle; applying energy to the heater of the evaporator; monitoring the air temperature of the heated air from the heater; limiting the oven temperature of the evaporator's oven chamber by changing the energy applied to the heater; and adjusting the heater temperature in response to changes in the heater's resistance to control the heater temperature.

[0010] An evaporator consistent with certain embodiments of the present subject includes an evaporator body comprising an outer shell; a heater located within the evaporator body configured to interfere with and heat the flow of air flowing in the region of the heater; an oven chamber fluidly coupled to the heater, wherein an evaporable material is held, the oven chamber being configured to be heated by the air heated by the heater, thereby causing the evaporable material to evaporate into the heated air; and a suction nozzle configured to deliver the heated air and the evaporated material.

[0011] Details of one or more variations of the subject matter described herein are set forth in the accompanying drawings and the following description. Other features and advantages of the subject matter described herein will become apparent from the specification, drawings, and claims. Although certain features of the currently disclosed subject matter have been described for illustrative purposes in relation to evaporator devices, it should be readily understood that these features are not intended to be limiting. The claims following this disclosure are intended to define the scope of the protected subject matter. Attached Figure Description

[0012] The accompanying drawings, which are included in and form part of this specification, illustrate certain aspects of the subject matter disclosed herein and, together with the specification, help to explain some principles associated with the disclosed embodiments. In the drawings: Figure 1A-1D External features of an exemplary evaporator device consistent with embodiments of the present subject are shown; Figure 2 Features of an exemplary evaporator device consistent with embodiments of the present topic are illustrated by exploded diagrams; Figure 3 Features of an exemplary evaporator device consistent with embodiments of the present topic are illustrated by cross-sectional views; Figures 4A-4E It shows Figure 3 Various features of exemplary evaporator devices; Figures 5A-5E Various features of an additional exemplary evaporator device consistent with embodiments of the present subject are shown; Figure 6 Features of a controller are shown, which can be adapted to regulate the temperature in an evaporator unit consistent with the implementation of the present subject. Figure 7 Features of a control circuit for regulating temperature in an evaporator apparatus consistent with an embodiment of the present subject are shown; Figure 8 A diagram illustrating the temperature profile of air in an evaporator apparatus consistent with an embodiment of the present subject is shown; Figure 9 It shows Figure 8 A more detailed view of a portion of the diagram; Figure 10 Features of an exemplary heater used with an evaporator apparatus consistent with embodiments of the present subject are shown; and Figure 11 A process flow diagram illustrating the characteristics of a method for adjusting and regulating the air temperature applied to an evaporable material in an evaporator apparatus consistent with an embodiment of the present subject is shown.

[0013] In fact, similar reference numerals indicate similar structures, features, or elements. Detailed Implementation

[0014] Embodiments of the present subject include methods and apparatus relating to the evaporation of one or more materials for inhalation by a user. The term "evaporator" is frequently used in the following description and refers to an evaporator device. Examples of evaporators consistent with embodiments of the present subject include electronic evaporators, electronic cigarettes, electronic cigarettes, etc. Typically, such evaporators are portable, frequently handheld devices that heat an evaporable material to provide an inhalable dose of the material.

[0015] Consistent with some embodiments of the present topic, the evaporator is a handheld device that primarily operates through convection to provide efficient transfer of heated air and rapid delivery of evaporable material to the user.

[0016] Consistent with certain embodiments of the present subject, the evaporator is constructed to allow very rapid heating (e.g., within 3 seconds, within 2 seconds, within 1 second, etc.) of the air drawn through the oven chamber, such that the evaporable material (e.g., living leaf plant material, etc.) within the oven chamber is heated to a target evaporation temperature. The oven chamber can be thermally conductive (to allow additional heating and evaporation of the material within the oven) or thermally insulated (to prevent heat transfer to the oven, so that heat is transferred only to the evaporable material). The oven chamber can be located at the distal end of the evaporator, opposite to the proximal suction nozzle. Alternatively, the oven chamber can be adjacent to or immediately adjacent to the suction nozzle, for example, located below or near the suction nozzle portion of the evaporator.

[0017] The oven chamber can be connected to the vicinity of the distal end of the evaporator via one or more contacts (e.g., to a frame or skeleton attached to the evaporator); however, some or most of the oven chamber may be surrounded by air gaps (or other thermal insulation devices, such as insulation material) to reduce heat transfer from the oven chamber to the rest of the evaporator. The oven chamber may include a lid. The oven chamber can be manufactured as a deep-drawn oven, for example, it may have depth, width, and span, wherein the depth of the oven chamber (the distance from the inside of the lid to the bottom (e.g., a screen)) may, for example, be between 0.3 and 2 times the width of the oven chamber; the span may be between 0.1 and 1 times the width. Typically, the dimensions of the oven chamber can be designed for the intended use of the evaporator assembly housing the oven chamber, and / or the dimensions of the oven chamber can be determined based on manufacturing considerations. The oven chamber may have solid walls, perforated walls, a basket weave structure, or some other solid and open area construction, or a combination of these, configured to reasonably accommodate the material to be evaporated. The oven chamber can be configured to receive another internal container (not shown), which may contain an evaporable liquid or wax, etc.

[0018] A heater (e.g., a resistance heating element) may be positioned in an air path and configured to rapidly heat air passing around and / or through the heater. The heater may include one or more openings, passages, channels, slots, slits, etc., for allowing air to pass through and / or around the heater. One or more of these air passages may have irregular, serrated, fractal, protruding edges or the like, which may, together with and / or separately from the heater's construction, generate increased turbulent airflow through or around the heater, thereby increasing heat transfer to the air as it passes through / arounds the heater. In one embodiment, the heater may be an elongated tube extending along its long axis, having one or more slit regions along its length to generate turbulence in air passing laterally across and / or along the tube's long axis. In some variations, the heater may include one or more thin sheets or plates of material having multiple slots, slits, or slit regions through which air passes; these sheets may be folded, wrinkled, delaminated, etc.; alternatively, in some variations, the sheets are flat. In other variations, the heater may be a coil or string of resistive material, which may have surface variations, ridges, blades, etc. to increase the surface area, thereby improving heat transfer to the air flowing around and through the heater.

[0019] In some embodiments of the present subject matter, the heater can be controlled by a heater control circuit comprising four inputs; the first pair of inputs can correspond to the heater power leads / inputs; the second pair of leads / inputs can be offset from the heater power leads / inputs (and in some variations positioned between the heater power leads / inputs) and can be configured to sense the voltage drop across the region of the heating element. This four-point measurement control can be used to determine the temperature of the resistance heater with relatively fine resolution (e.g., within + / - 5°C, within + / - 4°C, within + / - 3°C, within + / - 2°C, etc.). Alternatively, a two-point temperature sensing system can be used, wherein the same leads used to apply the heater power current can also be applied with a smaller current to measure the voltage drop across the leads, thereby measuring the heater temperature at periods different from when the heater current is applied.

[0020] Furthermore, temperature sensors (e.g., thermocouples, infrared sensors, or the like) can be deployed within the airflow path downstream of the heater (e.g., between the heater and the oven chamber, inside the oven chamber, etc.) to sense the temperature of the air flowing into, through, or around the oven chamber and to evaporate the material within the oven chamber. In any variation described herein, the temperature control circuitry may receive input from the heater (e.g., the heater temperature obtained by measuring resistance at two or four points and thus) and may also receive input from one or more downstream airflow temperature sensors (e.g., one or more thermistors located at the inlet where the heated airflow enters the oven chamber). The temperature control circuitry can be configured to immediately deliver increased power (current) to the heater at a first frequency / duty cycle upon sensing a negative pressure caused by the user drawing air onto the nozzle. This increased power can increase the heater temperature almost immediately (e.g., >500°C), but can be limited by the control circuitry to remain below a safe limit (e.g., 700°C) or within a useful temperature range. The control circuit can further monitor the temperature of the heated air that has passed through the heater before entering the oven chamber (e.g., via one or more thermistors), and can limit the temperature of the oven chamber (e.g., by changing the frequency / duty cycle of the applied power and / or the power applied to the heater) as part of the control loop. Therefore, the evaporation temperature, corresponding to the temperature of the air applied to the material within the evaporation oven chamber, can be maintained at the desired target temperature, or within the desired or useful temperature range.

[0021] The target temperature can be predetermined (e.g., preset on the device) and / or user-selected or user-modified. The target temperature can be a single temperature or multiple temperatures, including temperature profiles (e.g., multiple temperatures over time) or an acceptable temperature range. Users can input an absolute temperature (e.g., Celsius or Fahrenheit) or can adjust a predetermined temperature (up or down).

[0022] Typically, evaporators consistent with some embodiments of the present subject can be configured for use with removable or liquid or wax or other evaporable materials. Any of these evaporators can be configured to wirelessly connect to one or more devices, including user control devices, to modify the operation of the evaporator device. For example, the evaporators described herein can wirelessly communicate with user interfaces that allow dose control (dose monitoring, dose setting, dose limiting, user tracking, etc.), location information (e.g., location of other users, retailer / commercial location, evaporation location, etc.), evaporator personalization (e.g., naming the evaporator, locking / password protecting the evaporator, parental controls, associating the evaporator with user groups, registering the evaporator, etc.), and engaging in social activities (games, groups, etc.) with other users.

[0023] Evaporators consistent with the embodiments described in this paper may include a stacked arrangement of circuit boards, batteries, and other components. The oven chamber can be relatively large compared to the overall size of the evaporator unit, but has a relatively small thermal mass, allowing it to heat rapidly (e.g., in one second or less) to the evaporation temperature of the material (e.g., between 100°C and 300°C for tobacco). Therefore, the relative size / ratio of the oven chamber can be larger compared to other evaporators. In general, the evaporator may be thin and small. Because the evaporator can heat to vapor rapidly (in one second or less), and energy losses due to the thermal mass around the convective heating path can be kept relatively low, a user inhaling (or if the evaporator is lip-sensor activated) (or, alternatively, the user turning it on (e.g., selecting or pressing a button, etc.)) may only require three to four seconds of inhalation to obtain a satisfactory amount of vapor almost immediately, thus effectively replicating the effect of traditional combustion-based cigarettes, cigars, pipes, etc., thereby increasing user satisfaction.

[0024] Consistent with some implementations of the present topic, the evaporator can have a large or even unlimited number of customizable temperature settings. The number of sessions per charge, the number of user suctions per charge, and the charging time of the evaporator unit can be based on the size of the battery used.

[0025] refer to Figure 1A-1D The figure illustrates the external features of an exemplary evaporator device 100 consistent with embodiments of the present subject. As shown, the evaporator 100 may have an elongated or generally rectangular shape, with the length of its two opposite end portions shorter than the length of its two opposite side portions. However, variations in the size and shape of the evaporator consistent with embodiments of the present subject are possible. For example, the evaporator 100 may be substantially square, tubular, spherical, faceted, oval, or other shapes, or combinations thereof. Evaporators consistent with implementations of the present subject may be compact and sized for easy configuration in the user's hand, such as... Figure 1B As shown. The evaporator 100 has a housing 114, a suction nozzle 122 located at the top (or proximal) end 120, and a cover 110 located at the bottom (or distal) end 130. Figure 1D As shown, an air inlet vent 160 is provided on the housing 114 and extends through the housing 114. A Universal Serial Bus (USB) charging port 170 is also provided, extending through the housing 114.

[0026] Figure 2 Several features of the evaporator 100 are shown in an exploded view. The interior of the outer casing 114 is the structural housing component 212. One or more side air passages 215 ( Figure 2One of the components shown may be formed in one or more corresponding side surfaces of the structural housing component 212. Consistent with some embodiments of the present subject, the structural housing component 212 may be made of ceramic material, other insulating material, or other material (e.g., metal) that insulates the heater. The battery 240 and the printed circuit board (PCB) 216 are stacked and contained within the structural housing component 212. A portion of the oven chamber 201 surrounding the housing 213 is also contained within the structural housing component 212 near the end 130 of the evaporator 100. Electrical leads 205 are shown extending from within the housing 213. A cover 110 covers the opening of the oven chamber 201. A suction nozzle 122 is located at the end 120 of the evaporator 100.

[0027] Figure 3 Several features of the evaporator assembly 300 are shown in a cross-sectional view. For example... Figure 3 As shown, the evaporator 300 includes an internal oven chamber 301 near (e.g., almost adjacent to or adjacent to) its bottom end 330, which has an surrounding oven housing 313. A lid 310 engages or is otherwise attached to the outer housing 314 at the bottom end 330. A suction nozzle 322 engages or is otherwise attached to the outer housing 314 at its top end 320. Inside the outer housing 314 is a structural housing component 312. One or more internal side channels or passages 309 are formed between the outer side wall of the structural housing component 312 and the inner side wall of the outer housing 314 and extend along the length of both the outer side wall of the structural housing component 312 and the inner side wall of the outer housing 314. The internal passages 309 extend from the oven chamber 301 to the suction nozzle 322, thereby providing a cooling passage for evaporable material to be inhaled by a user.

[0028] Heater 302 is a flat-plate heater that allows for rapid heating and is capable of high watt density (e.g., ~60 W / in2) and high operating temperature limit (~700 °C), driven by the melting point of the dielectric.

[0029] Figures 4A-4E It shows Figure 3 Various features of the exemplary evaporator 300. Figure 4A The features of the oven chamber 301 and the heater 302 are shown in cross-sectional views, and Figure 4B and 4C The airflow through the evaporator is shown, consistent with some embodiments of the present subject. As shown, heated air flows upward from heater 302 through oven chamber 301 containing evaporable material and recirculates around the edge of oven chamber 301. Power lead 305 is shown connected to heater 302.

[0030] In some implementations of the current topic, such as Figure 4AAs shown, the heat conduction path passes through a flange of oven chamber 301, which may have a bottom with multiple perforations (e.g., a screen 315). The openings through the bottom can be patterned to uniformly distribute heated air, for example, with a larger pore density pattern in the outer region than in the inner region, or other variations for equal or near-equal heat distribution. The inlet air path may circulate around the exterior of oven chamber 301 to recover any heat from oven chamber 301. Heater 302 may be mechanically trapped between the bottoms of two deep-drawn components (e.g., a deep-drawn SS oven with another deep-drawn component welded to it). Heater 302 may be welded and / or brazed to oven chamber 301, or may be mechanically trapped. In some embodiments of the present subject, heater 302 may include a "thick-film heater" anchored only at the coldest point.

[0031] Figures 4A-4E Additional features around the oven chamber 301 and the evaporator 300 are also shown, such as the outer casing 314, structural housing component 312, and cover 310. Two spring-loaded power leads 305 and an air inlet 360 are also shown.

[0032] refer to Figure 4B and 4C The screen 315 can be installed inside the oven chamber 301 to prevent evaporable materials from contacting the flat plate heater 302. The heater 302 can be located ~1mm below the screen 315 (e.g., between 0.5mm and 5mm, or between 0.5mm and 3mm). The screen 315 and the heater 302 can be constrained by peripheral welding or other means. Figure 4B and 4C The air path from the inlet air hole 360 ​​to the heater 302 is shown, which circulates below the heater 302, then passes through the heater 302, then reaches above the heater 302, and then enters the oven chamber 301 upwards.

[0033] Heater 302 can be a low-mass composite structure. Figure 4D An enlarged view of an exemplary heater structure is shown, while Figure 4E The airflow path is shown. The substrate 450 of heater 302 can be, for example, 0.003” 430 stainless steel. Each side of heater substrate 450 may be coated with a glass dielectric thin layer 452 of ~0.002-0.003”. The bottom layer of heater 302 is a resistance heating element 454, which may be made of a silver-palladium alloy of ~0.001” thickness. A glass dielectric thin layer (not shown) may also be applied to the resistive element to mitigate oxidation damage. These glass and resistive layers can be applied using screen printing processes, for example, as a paste.

[0034] In an embodiment, heater 302 may include a stainless steel (SS) substrate with a glass dielectric layer and screen-printed resistive traces with a total thickness of ~0.10”.

[0035] exist Figure 3-4E In the operation of the evaporator 300 shown, the user can remove the lid 310, load the oven chamber 302 with the material to be evaporated, replace the lid 310, and draw air from the evaporator 300 on the opposite side of the oven chamber 301, where the suction nozzle 322 is located. When the user draws air from the suction nozzle 322, ambient air enters the evaporator through the inlet air hole 360 ​​of the housing 314, passes through the structural housing component 312 (e.g., a skeleton) that provides structural support for the oven chamber 301 and other internal components, and enters the oven chamber 301 around the cutout 332 for the power lead 305, thereby creating a pressure drop within the device, which can be measured by a pressure sensor (not shown). When this pressure drop is detected, the heater 302 is powered by allowing current to flow through the spring-loaded portion 335 of the power lead 305, causing the temperature of the resistive element of the heater 302 to rise rapidly. Air drawn into the oven chamber 301 passes below the heater 302, through the central hole 337 in the heater 302, and is heated as it is deflected over the top of the heater 302 by the non-porous area of ​​the screen 315. The remainder of the screen 315 is perforated to allow the hot air to easily pass through the material in the oven chamber 301 before exiting the top of the oven chamber 301 and flowing downwards to the side passages 309 in the frame (skeleton) to reach the user. The increased air turbulence generated by the structure of the evaporator 300, including the airflow across the lower portion of the heater 302, through the central hole 337 (or any number of other holes) of the heater 302, then to the upper surface of the heater, and then through the screen 315 into the oven chamber 301, allows for efficient heat transfer from the heater 302 to the air to the evaporable material, thereby improving evaporation efficiency and time.

[0036] To minimize energy loss from heater 302, oven chamber 301 can be of very low mass (<0.25mm wall thickness) and can be thermally insulated. For example... Figure 4A As shown, a small air gap 304 may exist between the oven chamber 301 and the structural shell component 312, which serves as insulation, thereby helping to prevent heat loss (heat transfer) from the heater 302 into the outer shell 314. In this way, much of the energy from the heater 302 in the form of heat will pass through the material to be evaporated rather than the body of the evaporator 300, or this heat will be transferred to the oven chamber 301 itself, which will also contribute to evaporation (through conduction heating).

[0037] exist Figure 3-4EIn the example, thermocouples are not shown; however, one or more thermocouples may be suspended inside or above the central hole 337 in heater 302, or somewhere within oven chamber 301. This provides closed-loop control of the air temperature. While not strictly necessary, the thermocouples will allow for faster steam generation since heater 302 can initially operate at a higher temperature, and then the temperature will slope down once the thermocouples indicate the desired evaporating air temperature.

[0038] An evaporator consistent with embodiments of the present subject may include a resistance heating element (e.g., heater 302) powered by current via two terminals (e.g., power lead 305). A precision resistance measurement circuit may be used to track the resistance of heater 302 when not heating and when heating, in order to control the temperature of heater 302 based on changes in the resistance of the heater material.

[0039] In some embodiments of the present topic, the evaporator 300 has an "on" / activated mode, but ideally, the heater 302 is triggered only by triggering a pressure / flow sensor, by capacitive lip sensing, or by the user pressing a use button, etc.

[0040] Figures 5A-5E Features of another exemplary evaporator 500, consistent with some implementations of the present topic, are shown through various views. Figure 5A and 5B A cross-sectional view is shown through the front view of the evaporator 500, which shows the heater assembly and the oven assembly, which can replace Figures 1 to 12. Figure 4E The heater and oven chamber are shown in the evaporator embodiment illustrated. Consistent with the implementation of the present subject, the evaporator 500 is constructed as an on-demand, convection-based evaporator. Figure 5C An exemplary notched tube heater 502 is shown. Figure 5D A top perspective view of the evaporator 500 is shown, which shows details of the oven chamber 501. Figure 5E The airflow through evaporator 500 is shown.

[0041] Evaporator 500 includes an oven chamber 501 having an evaporable material that can be contained within an oven housing 513; this material may be packaged or otherwise inserted into the oven chamber 501. The oven chamber (or oven) 501 may be formed by a progressive forming process. Evaporable material (including removable evaporable material) may be stored in the oven chamber 501 for evaporation. Evaporator 500 may also include an oven lid 510 that may cover, close, and / or seal the loading side of the oven chamber 501. The oven lid 510 may be attached to an accessible portion of the oven chamber 501 by various mechanisms, including friction fit, magnetic attachment, mechanical attachment, and some combination thereof. Evaporator 500 also includes a notched tubular heater 502 (e.g., a heating assembly, a convection heating assembly) that includes a heating element that may be directly adjacent to or nearly adjacent to (e.g., in) the oven. Figure 5A and 5B The oven chamber 501 (located below) is used for placement and can be situated within an open chamber or cavity 507 of the elongated, flat body of the evaporator 500. The notched tubular heater 502 can be a tube made of a resistance metal alloy, cut or slotted by processes such as laser etching. The notched region 555 can provide higher resistance than the rest of the tube, allowing air (e.g., air drawn in by the user) to pass through the slot with relatively greater turbulence before contacting the evaporable material. The notched tubular heater 502 can be held in the air path and coupled to the cavity 507 of the evaporator 500 via a small number of contact points, or thermally or electrically insulating couplings, insulating linings, etc., to minimize heat transfer.

[0042] In operation, the evaporator 500 can be loaded with evaporable material by removing the oven lid 510 to load the oven chamber 501 with the desired evaporable material. The user can then replace the oven lid 510 and perform suction from the evaporator 500 on the opposite side of the oven chamber 501, where the suction nozzle (e.g., Figure 2 The suction nozzle 122 shown is located on the opposite side. When the user draws air through the suction nozzle, ambient air passes through the air inlet 160 of the housing 514 and the air inlet 160 of FIG. 1. Figure 4AAn inlet air vent of the same type as the inlet air vent 360 enters the evaporator 500. The outer casing 514 can be a protective shell or other extrusion (including aluminum extrusions); and can pass through a support shell (e.g., a support fixture or frame) 512 within the outer casing 514 (which can provide structural support for the notched tubular heater 502 and the oven chamber / heater casing 517), thereby entering the cavity 517 and generating a pressure drop detected by the pressure sensor 508. When this pressure drop is detected, the notched tubular heater 502 can be powered by passing current through the power lead 505 through the notched tubular heater 502, thereby causing the temperature of the notched or slotted region 555 of the notched tubular heater 502 to rise rapidly. Air drawn into the cavity 507 can flow into the tubular structure of the notched tubular heater 502, and the temperature rises as the air passes through the tube extension and the notched region 555. As air passes through the notch region 555 of the notch heater 502, it begins to flow upward over the thermocouple sensor 503, which is suspended near the bottom of the oven chamber 501 by a screen 515. The screen 515 is perforated to allow hot air to easily pass through the material in the oven chamber 501 before exiting the top of the oven and flowing downward to the side grooves 509 formed by the support housing 512 (e.g., a support frame or skeleton) and reaching the suction nozzle located at the opposite end for inhalation by the user.

[0043] To minimize energy loss from the notched tubular heater 502, both the notched tubular heater 502 and the oven chamber 501 can be housed in a low thermal conductivity material such as zirconium oxide. The walls of the oven chamber / heater housing 517 can be relatively thin to reduce the amount of material-related thermal mass. Figure 5A As shown, a small air gap 504 exists between the oven chamber 501 and the oven chamber / heater housing 517, which can serve as insulation (or may include insulation material) to help prevent heat loss (heat transfer) into the oven chamber / heater housing 517. In this way, most of the energy in the form of heat will pass through the material to be evaporated rather than the body of the evaporator 500 (e.g., the outer casing 514).

[0044] The notched tube heater 502 can be a resistance heating element that heats the air by a current passing between two terminals 505, wherein the notched tube heater 502 is connected to a power supply lead 505. The notched tube heater 502 can be a hollow, elongated tube (having any suitable cross-sectional shape, including circular, elliptical, rectangular, square, etc.); the tube can be straight, curved, or bent (including folds in itself), and can include one or more slits or openings in the lateral side of the elongated tube through which air can be drawn in. The tube of the notched tube heater 502 can be arranged generally transversely to the air path of the evaporator 500, such that drawing air from the nozzle pulls the air through the slits or openings, thereby both heating the air and generating turbulent airflow through the notched tube heater 502, which can mix the heated air to prevent localized hot / cold spots.

[0045] The evaporator 500 may also include precision resistance measurement circuitry to track the resistance of the notch heater 502 when not heated and / or when heated, in order to control the temperature of the notch heater 502 based on the change in element resistance from room temperature to evaporation temperature. This measurement circuitry may be a multi-terminal (e.g., four-terminal) sensing system that uses, for example, test lead 506 to sense the voltage drop across a region of the notch heater 502, such as across the notch region 555 of the notch heater 502, when a test current (e.g., a small but known constant current) is applied through test lead 506. This applied test current may be different from the heating current used to heat the notch heater 502 to a high temperature through power lead 505 and may be applied to the notch heater 502 during measurements between heating cycles.

[0046] In the exemplary evaporator 500, the measurement circuitry can be configured to provide four-point resistance measurements, and in some cases, this circuitry can provide more accurate resistance measurements than a two-terminal resistance sensing circuit. The four-point measurement circuitry can ignore heat conduction caused by high current (when the power supply leads are soldered to the heater tube) and resistance changes in the power supply leads caused by electrical heating. In some configurations, a two-terminal resistance measurement circuit may not accurately compensate for resistance changes in the power supply leads, resulting in inaccurate temperature calculations.

[0047] Figure 6The controller is shown to be adapted to regulate the temperature in an evaporator unit consistent with the implementation of the present subject. Block diagram 600 includes measurement (e.g., control) circuitry 620 that measures the resistance of a resistance heater (e.g., notch-tube heater 502) and provides an analog signal to a microcontroller 610. Inputs from thermocouple sensor 503 to the microcontroller 610, as well as inputs from sensors (e.g., pressure sensor 508, buttons, or any other sensors), can be used by the microcontroller 610 to determine when the notch-tube heater 502 should be heated, for example, when a user is pumping on the evaporator 500, and when the unit should be set to a warmer temperature (e.g., standby temperature). Figure 6 In the example, the signal from the measurement circuit 620 is shown in... Figure 7 As shown, it directly reaches the microcontroller 610.

[0048] Consistent with the implementation method of the current topic Figure 6 The example provides the electrical energy transfer from a power source (which may be part of the evaporator 500) to the notch-tube heater 502. Additionally, an extra input may be a desired temperature input 630, which is determined and entered by the user and used by the microprocessor 610 as described below. The desired temperature input can be pre-established and input to the microcontroller 610, rather than being input by the user.

[0049] Figure 7 Features of a measuring circuit 620 for regulating the temperature in an evaporator apparatus consistent with the implementation of the present subject are shown.

[0050] To accurately control the temperature of a resistive element during heating, relatively high resolution in the resistance measurement can be helpful. Based on the temperature coefficient of resistance (TCR) of the metal alloy used for the heating element, a change of only a few milliohms (mΩ) can represent a change of more than 100°C. To achieve high-resolution measurement of such temperature changes, scalable resistance measurement circuits (e.g., four-point resistance measurement circuits) can be used. Figure 7 An example circuit diagram for constructing a resistance measurement circuit as a four-point resistance measurement circuit is shown. Figure 7 As shown, a power supply 720 is provided. In operation, the circuit can enable the metal-oxide-semiconductor field-effect transistor (MOSFET) Q10 704, which allows a small current from the current source U2 706 to pass through the heating element 702 (which passes through terminals HI+ and HI- via...). Figure 5A The power supply leads 505, used to provide higher heating current, are connected to the circuit respectively, where they can be connected via HV+708 and HV-708' leads (via...). Figure 5A and 5BThe test lead 506 shown detects the voltage drop across the heating element. This low voltage drop (tens of millivolts) is sensed by a first stage of an amplifier circuit (U12A) 710, which can be configured as a unity-gain differential amplifier. High resolution for resistance measurement is achieved by a second stage of a scaling amplifier circuit (U12B) 712. A selectable scaling factor 714 selectively switches (under the control of microcontroller 610) a specific combination of MOSFETs Q5-Q9 to scale the input to the second-stage amplifier, which can be configured as a non-inverting amplifier with fixed gain, allowing for even higher resolution for heater resistance measurement. In contrast to the first stage, the second stage of the scaling amplifier circuit ensures that the scaling resistors R10-R14 have little or no effect on the closed-loop gain of the differential amplifier. This is desirable because the differential stages should preferably remain symmetrical for accurate measurement of the differential voltage across the heating element. Furthermore, the circuit also has the ability to measure the thermoelectric or Seebeck effect that occurs when two different metals are at different temperatures. This allows the evaporator to compensate for the Seebeck effect. For example, using a microcontroller-based analog-to-digital converter (ADC), the output voltage of a second-stage amplifier can be sampled and converted into a binary representation, which can then be used in a lookup table to convert these readings into resistances. The lookup table can be theoretically determined (e.g., based on circuit analysis); and it can be corrected using measurements of the Seebeck effect and some fixed offset caused by component tolerances.

[0051] Consistent with some embodiments of the present subject, the evaporator can adjust and regulate the air temperature applied to the evaporable material. In any variation described herein, the evaporator device can be configured to allow the user to select (desired temperature input 630) different air temperatures to evaporate the material of interest (e.g., via buttons or other control inputs on the device, or wirelessly, e.g., via a user interface on a remote device, such as a smartphone communicating with the evaporator). Evaporator control circuitry (e.g., Figure 6 The block diagram 600 may include one or more controllers to adjust the overall temperature selection.

[0052] Specifically, the microcontroller 610 can use a first controller circuit (control law) to regulate the temperature of the notch-tube heater 502 (resistance heater) to control and rapidly heat the resistance heater and estimate its temperature based on the resistance heater's TCR; and a second controller circuit (control law) can further regulate the resistance heater based on a user-selected or predetermined evaporation temperature (e.g., between 200°C and 500°C), which can be sensed by one or more thermocouple sensors 503 in the airflow path (e.g., downstream of the resistance heater and / or located between the resistance heater and the oven chamber). These two controller circuits can cooperate to regulate the heating temperature or heating rate by adjusting the duty cycle of the energy applied to the heater.

[0053] For example, a proportional-integral-derivative (PID) controller can be implemented on microcontroller 610, which monitors thermocouple sensor 503 above notch heater 502 and uses thermocouple sensor 503 as a feedback mechanism for the air temperature controller. Separately, a second PID controller can be used to regulate the temperature of notch heater 502 by determining the target resistance setpoint of the notch heater 502 using the TCR of the (resistance heater) metal alloy, ensuring that notch heater 502 does not exceed a safe operating point. The two PID controllers can operate simultaneously, for example, at 128Hz, and control logic can be used to determine which PID controller (air temperature or heater temperature) output is used at any given point. The outputs of both PID controllers can be routed to power MOSFET 701 (e.g., Figure 7 The duty cycle of the pulse-modulated (PWM) signal input (Q2) in the schematic diagram alternates, with only one output used to control the transistor at a time. When the evaporator detects that the user has started suction (which can be detected from a pressure sensor, see example...), the evaporator... Figure 5AWhen the temperature of the heater element is detected by the thermocouple sensor 503 (or determined by a button pressed by the user), the heater temperature PID controller that senses the TCR can be initialized first. This ensures that the temperature of the heating element rises rapidly to its maximum operating temperature to heat the incoming air as quickly as possible. As described above, the temperature of the thermocouple sensor 503 is monitored, and when that temperature exceeds a predetermined threshold, the output of the air temperature PID controller is applied. For example, if the user sets the evaporation temperature to 350°C and continues to pump air onto the evaporator (the threshold used by the trigger pressure sensor to start pumping), the microcontroller will begin to pulse the power MOSFET using the duty cycle from the heater temperature PID controller to regulate the temperature of the heating element to the maximum allowable value of 700°C. When the incoming air is heated, once the detected air temperature exceeds the set threshold (e.g., corresponding to a temperature of, for example, 300°C), the air temperature PID controller controls the applied heater current. The heating element is then controlled by the air temperature PID controller to regulate the air temperature to 350°C, but the heater temperature PID controller will not allow the temperature of the heating element to exceed 700°C and will shut off. If the airflow is low enough to allow the heating element to reach its maximum safe operating temperature, the system can have two PID controllers alternate. That is, if the airflow is too high, the heater may not be able to reach its maximum temperature.

[0054] The above embodiments were tested using an airflow of 4 L / min through the heating element and the oven, while data from the thermocouples were recorded during the session. Figure 8 and 9 The curves at 800 and 900 are shown respectively. The thermocouple reaches the evaporation temperature in about one second. Figure 9 It shows Figure 8 A more detailed graph between 3 and 7 seconds shows the heating time. The control law operating on this evaporator uses resistance measurements of the heating element to ensure that the element does not exceed its safe operating temperature (e.g., 700°C). The evaporator continuously monitors the thermocouples and regulates the air temperature to the setpoint (350°C in this example). Overshoot may occur during heating, but this is likely intentional to allow the evaporable material to reach its evaporation temperature as quickly as possible. The coarse resolution of the following data is due to the minimum sampling time of the thermocouple monitors used in the device. However, this is sufficient to control the air temperature within at least ±5°C. More fine-grained control systems are also within the scope of this topic.

[0055] In some variations of the on-demand convection-based evaporator described herein, the resistance heater (resistance heating element) may be formed from one or more different types of metal alloys, such as stainless steel 316, stainless steel 309, nickel-chromium alloys, or any other resistance metal alloy. Alternatively or additionally, the housing for the resistance heating element and the oven may be made of metal or alloy, such as thin aluminum sheets or thin stainless steel sheets. The heating element may be insulated from the housing by a sleeve or bushing made of Teflon or a similar material.

[0056] In any of the variations described herein, the evaporator may include a heat exchanger in thermal communication with the heater, which allows for better efficiency. This may involve a circular metal baffle or disc that can be inserted into each side of the heating element tube and mounted near a recessed area, such as recess 555. Some of the heat conducted downstream of the tube away from the recessed area can also be conducted to these heat exchangers. As air is drawn through the ends of the tube, these alternative proposed heat exchangers can utilize some of the heat lost conducting downstream of the ends of the tube and return this otherwise “lost” energy to the drawn air. Another approach, similar to such a disc or baffle, includes protrusions or fins on the heater tube that project toward the center of the tube. These fins can provide another type of heat exchanger to help add heat back into the air path.

[0057] Consistent with some implementations of the present topic, a thermocouple can be built into the evaporator instead of incorporating the thermocouple sensor 503 into the evaporator 500. In one example, as an alternative to using a thermocouple for air temperature measurement, the temperature of the screen 515 can be measured. For example, if the screen 515 is insulated from the oven chamber 501, it can be used as a thermistor. Resistance can be measured through this lead, which includes a lead detached from either end along the long axis. This method allows the microcontroller 610 to calculate the average temperature of the screen 515, which, since the average temperature and air temperature should be highly correlated, can therefore be used as an alternative for air temperature measurement. As another example, if the screen 515 remains electrically connected to the oven chamber 501, individual leads of different materials can be pulled from the screen 515 to form a self-organizing thermocouple. The temperature at the junction between the two materials can be calculated by the microcontroller 610 by measuring the voltage across the oven chamber / screen construction and the leads of different materials. Alternatively, an infrared sensor inside or near the oven chamber can similarly measure the temperature of the air evaporating the material. Alternatively, the downstream air temperature sensor can be removed directly, and algorithms can be used to predict the downstream air temperature based on heater temperature, flow rate, and / or time.

[0058] Consistent with some embodiments of the present subject matter, the evaporator's oven chamber and suction nozzle do not need to be located at opposite ends of the evaporator. For example, the suction nozzle may be adjacent to or nearly adjacent to the oven chamber. In such a configuration, one or more air paths from the oven chamber connected to the suction nozzle (through which steam travels) can be configured to allow the steam to be adequately cooled before being delivered to the user via the suction nozzle. For example, a turbulent path for airflow may be provided after the oven chamber to allow adequate cooling. Such a turbulent path may include a zigzag path, a path with various ridges and / or protrusions, or other configurations or methods to allow relatively rapid heat exchange from the heated steam.

[0059] Figure 10 Another variation of the heater element 1000 is shown, wherein the heater is a flat plate heater with a thin, serpentine design, for example, made of a resistance metal alloy. This design can replace... Figure 3-4E The heater 302 is shown. In this design, the flat heating element can be placed directly in the air path below the oven chamber. (Alternative reference) Figure 5A and 5B The air path described above passes through a tube and then changes direction to exit the tube from the notched area. In Figure 10, the air path can be more direct. Air can enter the device from below the serpentine heater element 1000 and pass through the slot 1005 in the heater element 1000 before entering the oven chamber. Figure 5A As shown, a thermocouple sensor can be mounted between the heater element 1000 and the oven chamber to measure and control the air temperature before contacting or otherwise heating the evaporable material. In some variations, the heater (resistance heating element) can be a thin-film resistance heating element wound, bent, or otherwise configured with a suitable number (e.g., 1, 2, 3, 5, etc.) of through-passages, slits, slots, etc., to allow air to pass over and through the resistance heater for rapid heating. In any of these variations, the heater element 1000 can be held in the air path and coupled to the internal cavity of the device via a small number of contact points 1010 to minimize heat transfer; alternatively, the heater element 1000 can be connected via thermally and / or insulating couplings. In any of these variations, the heater's passages, slits, etc., or surface areas can have fractal, sawtooth, finned, or other features to further increase heat transfer to the air.

[0060] Reference Figure 11Process flow diagram 1100 illustrates the features of the method, which may optionally include some or all of the following: At 1110, suction by a user on the nozzle of the evaporator is detected (or, alternatively, by a user-selected button or other start indicator device). This detection may be performed using a pressure sensor in the airflow path of the ambient air entering the evaporator chamber. At 1120, energy is applied to the heater of the evaporator, initiating a process that rapidly increases the heater temperature to a high operating temperature or maximum operating temperature to quickly heat the incoming ambient air. At 1130, the temperature of the heated air from the heater is monitored. This monitoring may be performed using one or more thermocouple sensors between the evaporator heater and the oven chamber to determine the temperature of the air leaving the heater. At 1140, the oven temperature of the evaporator oven chamber is limited by varying the energy applied to the heater. This ensures that the heater does not exceed a predetermined threshold. At 1150, the heater temperature is adjusted in response to changes in the heater resistance to control the heater temperature.

[0061] As described above, implementations of the current subject matter include methods and apparatus for evaporating materials, allowing the materials to be inhaled by a user. The devices described herein include evaporator devices and systems including evaporator devices. In particular, on-demand convection evaporator devices (apparatus and systems) are described herein, which can be configured for user control and operation. The following description of exemplary embodiments is provided to illustrate various features that may be part of the current subject matter. They are not intended to be limiting.

[0062] For example, an on-demand handheld convection evaporator device may include: an elongated body with a protective shell; a nozzle located on the elongated body; a sensor for detecting suction through the nozzle; an oven chamber located within the elongated body, wherein the side walls of the oven chamber are surrounded by air gaps; a convection heater located within the elongated body, the convection heater having a plurality of slots and / or openings configured to allow air to pass through the convection heater and generate mixing turbulence as the air passes over and / or through the convection heater; a heater control circuit configured to heat the convection heater to a temperature greater than 500°C upon detection of suction through the nozzle; further, wherein the heater control circuit limits the heater to a maximum temperature; additionally, wherein air flowing from the heater into the oven chamber is heated to a target evaporation temperature.

[0063] The on-demand handheld convection evaporator device may include: an elongated body with a protective shell; a suction nozzle located at the proximal end of the elongated body; a sensor for detecting suction through the suction nozzle; an oven chamber located at the distal end of the elongated body, wherein more than 80% of the side walls of the oven chamber are surrounded by air gaps; a convection heater located within the elongated body, the convection heater having multiple slots and / or openings configured to allow air to pass through the convection heater and generate mixing turbulence as the air passes over and / or through the convection heater; a heater control circuit configured to heat the convection heater to a temperature greater than 500°C upon detection of suction through the suction nozzle; additionally, wherein the heater control circuit limits the heater to a maximum temperature; wherein air flowing from the heater into the oven chamber is heated to a target evaporation temperature greater than 200°C within 4 seconds of detecting suction through the suction nozzle.

[0064] Any of these evaporators may use a tubular convection heater, such as an elongated tube extending along its long axis, having multiple slit regions along its length to generate turbulence in the air passing through it. For example, an on-demand handheld convection evaporator device is described herein, which may include: an elongated body with a protective shell; a suction nozzle located at the proximal end of the elongated body; a sensor for detecting suction through the suction nozzle; an oven chamber located at the distal end of the elongated body, wherein more than 80% of the side walls of the oven chamber are surrounded by air gaps; a convection heater comprising an elongated tube extending along its long axis, having multiple slit regions along its length to generate turbulence in the air passing through it; heater control circuitry configured to heat the convection heater to a temperature greater than 500°C upon detection of suction through the suction nozzle; additionally, wherein the heater control circuitry limits the heater to a maximum temperature; wherein air flowing from the heater into the oven chamber is heated to a target evaporation temperature greater than 200°C.

[0065] Any of the evaporators and / or methods according to embodiments of the present subject matter may also include or utilize a heater control circuit including four-point measurement circuitry. For example, an on-demand handheld convection evaporator device may include: an elongated body with a protective shell; a nozzle located at the proximal end of the elongated body; a sensor for detecting suction through the nozzle; an oven chamber located at the distal end of the elongated body, wherein the side walls of the oven chamber are surrounded by air gaps; a convection heater having a plurality of slots and / or openings along its length to generate turbulence in the air passing through it; and a heater control circuit including four-point measurement circuitry having four leads coupled to the convection heater, wherein two of the leads are configured to sense a voltage drop across a region of the heating element, further wherein the heater control circuit is configured to heat the convection heater to a temperature greater than 500°C and limit the heater to a maximum temperature upon detection of suction through the nozzle; wherein air flowing into the oven chamber from the convection heater is heated to a target evaporation temperature.

[0066] Therefore, typically, when the device includes a four-point measurement circuit with four leads coupled to a convection heater, two of the leads can be configured to sense the voltage drop across the region of the heating element; these leads can be located between two external leads. The two external leads can supply power to the convection heater. For example, the first and second leads of the four leads of a heater control circuit can be configured to supply power to heat the convection heater. The two leads configured to sense the voltage drop can be spaced apart from the power supply leads such that a temperature rise due to the applied high power level will not affect the resistance / conductivity of the voltage sensing leads.

[0067] Any of the evaporators according to embodiments of the present subject matter may include a temperature sensor located between the interior of the convection heater and the oven chamber, wherein the temperature sensor provides an air temperature input to the heater control circuitry.

[0068] Typically, the heater control circuit can be configured to control the energy applied to the convection heater based on the temperature of the convection heater and the air temperature between the convection heater and the oven chamber.

[0069] In any of these devices, the suction nozzle may be located at the proximal end of the elongated body, and the oven chamber may be located within the distal end of the elongated body.

[0070] The apparatus according to embodiments of the present subject matter can be configured to heat air immediately or almost instantaneously to evaporate materials in the oven chamber. For example, air flowing into the oven chamber from the heater can be heated to a target evaporation temperature greater than 200°C within 4 seconds (e.g., within 3 seconds, within 2 seconds, within 1 second, etc.) after suction is detected through the nozzle.

[0071] The side walls of the chamber may be surrounded by air gaps such that the sides of the chamber (e.g., the side walls perpendicular to the bottom of the oven chamber) are surrounded by air gaps for at least 50% (e.g., at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 95%).

[0072] Methods of operating any of the devices described herein may include methods of evaporating materials. For example, a method of operating an on-demand handheld convection evaporator may include features such as: sensing suction at the evaporator's suction nozzle; applying energy to a conductive heater of the evaporator; adjusting the energy applied to the conductive heater based on four-point measurements, said four-point measurements including a first pair of inputs corresponding to a first pair of leads connected to the conductive heater and a second pair of inputs corresponding to a second pair of leads connected to the conductive heater, wherein the second pair of leads is offset from the first pair of leads; and evaporable materials within the oven chamber of the evaporator.

[0073] A conductive heater that applies energy to the evaporator may include raising the temperature by more than 200 degrees Celsius in about one second, and / or applying energy from a first pair of leads. A second pair of leads may be positioned between the first pair of leads.

[0074] Any of these methods may also include determining the temperature of the conductive heater from measurements at four points.

[0075] Adjusting the energy applied to a conductive heater based on four-point measurements can include adjusting the frequency and / or duty cycle of the energy applied to the conductive heater.

[0076] Any of these methods may also include adjusting the energy applied to the conductive heater based on the air temperature between the convection heater and the oven chamber of the evaporator, and / or sensing the air temperature between the convection heater of the evaporator and the oven chamber.

[0077] Any of these methods may also include limiting the energy applied to the conductive heater so that the temperature of the conductive heater does not exceed a maximum threshold (e.g., 500°C, 550°C, 600°C, 650°C, 700°C, 750°C, etc.).

[0078] For example, a method of operating an on-demand handheld convection evaporator may include: sensing suction at the evaporator's nozzle; applying energy from a first pair of leads to a conductive heater of the evaporator to raise the temperature by more than 200 degrees Celsius in about one second; adjusting the energy applied to the conductive heater based on four-point measurements, the four-point measurements including a first pair of inputs corresponding to the first pair of leads and a second pair of inputs corresponding to a second pair of leads connected to the conductive heater, wherein the second pair of leads is positioned between the first pair of leads; adjusting the energy applied to the conductive heater based on the air temperature between the evaporator's convection heater and the oven chamber; and evaporating the evaporable material within the evaporator's oven chamber.

[0079] When a feature or element is referred to herein as "located on another feature or element," it may be directly located on the other feature or element, or there may be intermediate features and / or elements present. Conversely, when a feature or element is referred to herein as "directly located on another feature or element," there are no intermediate features or elements. It should also be understood that when a feature or element is referred to herein as "connected," "attached," or "coupled / coupled" to another feature or element, it may be directly connected, attached, or coupled / coupled to the other feature or element, or there may be intermediate features or elements present. Conversely, when a feature or element is referred to herein as "directly connected," "directly attached," or "directly coupled / coupled" to another feature or element, there are no intermediate features or elements.

[0080] Although one embodiment has been described or illustrated, the features and elements thus described or illustrated may be applied to other embodiments. Those skilled in the art will also understand that references to structures or features positioned “adjacent” to another feature may have portions overlapping or located beneath the adjacent feature.

[0081] The terminology used herein is for the purpose of describing particular implementations and achieved, and is not restrictive. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” as used herein are intended to include the plural forms as well. It will be further understood that, when used in this specification and claims, the terms “comprising” and / or “including” specify the presence of the said features, steps, operations, elements, and / or devices, but do not exclude the presence or addition of one or more other features, steps, operations, elements, devices, and / or groups thereof.

[0082] In the foregoing description and claims, phrases such as "at least one" or "one or more of..." may appear as a combined list of elements or features. The term "and / or" may also appear in a list of two or more elements or features. Unless otherwise implicitly or explicitly contradicted by the context in which it is used, such phrases are intended to individually refer to any listed element or feature, or any listed element or feature in combination with any other listed element or feature. 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." A similar interpretation applies to lists comprising three or more items. For example, the phrases "at least one of A, B, and C," "one or more of A, B, and C," and "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." The use of the term "based on" in or in the claims means "at least partially based on," thus allowing for the inclusion of unreferenced features or elements.

[0083] In the case of this specification, spatially relative terms such as “below,” “below,” “above,” “over,” etc., may be used to describe the relationship of an element or feature to other elements or features as shown in the figures. It should be understood that, in addition to the orientations shown in the figures, spatially relative terms are intended to include different orientations of the device in use or operation. For example, if the device in the figure is reversed, an element described as “below” or “below” other elements or features would be “oriented” “above” other elements or features. Thus, the exemplary term “below…” can include both above and below orientations. The device may be oriented in other ways (rotated 90 degrees or otherwise), and the spatially relative descriptors used herein shall be interpreted accordingly. Similarly, unless explicitly stated otherwise, the terms “up,” “down,” “vertical,” “horizontal,” etc., are used herein for illustrative purposes only.

[0084] Unless the context otherwise requires, although the terms “first” and “second” may be used herein to describe various features / elements (including steps), these features / elements should not be limited by these terms. These terms are used to distinguish one feature / element from another. Thus, the first feature / element discussed below may be referred to as the second feature / element, and similarly, the second feature / element discussed below may be referred to as the first feature / element without departing from the teachings provided herein.

[0085] As used in this specification and claims, including as used in the embodiments, and unless explicitly stated otherwise, all numbers may be read as beginning with the word “about” or “approximately”, even if the term is not explicitly stated. The phrase “about” or “approximately” may be used when describing magnitude and / or location to indicate that the described value and / or location is within a reasonable expected range of value and / or location. For example, a numerical value may be the value (or range of values) + / - 0.1%, the value (or range of values) + / - 1%, the value (or range of values) + / - 2%, the value (or range of values) + / - 5%, the value (or range of values) + / - 10%, etc. Unless the context otherwise requires, any numerical value given herein should also be understood to include approximately or approximately that value. For example, if the value “10” is disclosed, “about 10” is also disclosed. Any numerical ranges referenced herein are intended to include all subranges contained therein. It should also be understood that, as those skilled in the art will appropriately understand, when a value is disclosed, "less than or equal to that value," "greater than or equal to that value," and the possible range between the value are also disclosed. For example, if the value "X" is disclosed, then "less than or equal to X" and "greater than or equal to X" (e.g., where X is a numerical value) are also disclosed. It should also be understood that throughout the application, data is provided in a variety of different formats, and that the data represents a range of any combination of end points and start points, as well as data points. For example, if specific data point "10" and specific data point "15" are disclosed, then it should be understood that greater than, greater than or equal to, less than, less than or equal to, and equal to 10 and 15, as well as between 10 and 15, are also considered disclosed. It should also be understood that each unit between two specific units is also disclosed. For example, if 10 and 15 are disclosed, then 11, 12, 13, and 14 are also disclosed.

[0086] Although various illustrative embodiments have been described above, any changes may be made to these embodiments without departing from the teachings herein. For example, in alternative embodiments, the order in which the various described method steps are performed may often be changed, and in other alternative embodiments, one or more method steps may be skipped entirely. Optional features of various apparatus and system implementations may be included in some embodiments but not in others. Therefore, the foregoing description is provided primarily for illustrative purposes and should not be construed as limiting the scope of the claims.

[0087] One or more aspects or features of the subject matter described herein can be implemented in digital electronic circuits, integrated circuits, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), computer hardware, firmware, software, and / or combinations thereof. These various aspects or features can be implemented in one or more computer programs executable and / or interpretable on a programmable system, which includes at least one programmable processor, which may be dedicated or general-purpose, coupled to receive data from a storage system, at least one input device, and at least one output device, and to send data and instructions to the storage system, at least one input device, and at least one output device. The programmable system or computing system may include clients and servers. Clients and servers are typically geographically separated and typically interact via a communication network. The client-server relationship is established by means of computer programs running on respective computers and having a client-server relationship with each other.

[0088] These computer programs, also referred to as programs, software, software applications, applications, devices, or code, include machine instructions for a programmable processor and can be implemented using high-level procedural languages, object-oriented programming languages, functional programming languages, logic programming languages, and / or assembly / machine languages. As used herein, the term "machine-readable medium" refers to any computer program product, device, and / or apparatus for providing machine instructions and / or data to a programmable processor, such as disks, optical disks, memories, and programmable logic devices (PLDs), including machine-readable media that receive machine instructions as machine-readable signals. The term "machine-readable signal" refers to any signal used to provide machine instructions and / or data to a programmable processor. Machine-readable media can store such machine instructions non-transitory, such as non-transitory solid-state memory or magnetic hard disk drives or any equivalent storage medium. Machine-readable media can alternatively or additionally store such machine instructions transiently, such as processor caches or other random access memory associated with one or more physical processor cores.

[0089] To provide interaction with a user, one or more aspects or features of the subject matter described herein can be implemented on a computer having a display device (such as a cathode ray tube (CRT), liquid crystal display (LCD), or light-emitting diode (LED) monitor for displaying information to the user) and a keyboard and indicating devices (such as a mouse or trackball) from which the user can provide input to the computer. Other types of devices may also be used to provide interaction with a user. For example, feedback provided to the user can be any form of sensory feedback, such as visual, auditory, or tactile feedback; and input from the user can be received in any form, including but not limited to acoustic, voice, or tactile input. Other possible input devices include, but are not limited to, touchscreens or other touch-sensitive devices, such as single-point or multi-point resistive or capacitive touchpads, voice recognition hardware and software, optical scanners, optical pointers, digital image capture devices, and associated interpretation software.

[0090] The examples and illustrations included herein show specific embodiments in which the subject matter can be practiced by way of illustration and not limitation. As stated above, other embodiments can be utilized and derived therefrom, allowing for structural and logical substitutions and changes without departing from the scope of this disclosure. Such embodiments of the subject matter of this invention may be referred to herein individually or collectively by the term "invention," and if more than one invention is disclosed in fact, it is not intended to voluntarily limit the scope of this application to any single invention or inventive concept but merely for convenience. Thus, although particular embodiments have been illustrated and described herein, any arrangement calculated to achieve the same purpose may substitute for the particular embodiments shown. This disclosure is intended to cover any and all modifications or variations of the various implementations. After reading the above description, combinations of the above embodiments, as well as other embodiments not specifically described herein, will be apparent to those skilled in the art.

Claims

1. An evaporator, comprising: Evaporator body, which includes an outer casing; A heater located within the evaporator body, the heater having at least one opening through which air passes and is heated; An oven chamber containing an evaporable material, the oven chamber being heated by air heated by the heater, such that the evaporable material evaporates at least partially into the heated air; A controller, coupled to the heater and configured to heat the heater to a temperature; as well as The nozzle is configured to deliver the heated air and the evaporated material.

2. The evaporator according to claim 1, further comprising an inlet air opening formed through a portion of the outer casing, wherein air enters the evaporator body through the inlet air opening when a user draws through the nozzle.

3. The evaporator of claim 2, further comprising a pressure sensor configured to detect airflow, wherein the pressure sensor is coupled to the controller and sends a signal to the controller when the airflow is detected.

4. The evaporator of claim 3, wherein the signal causes the controller to heat the heater.

5. The evaporator according to any one of claims 1-4, further comprising a structural housing for the heater, the structural housing surrounding at least a majority of the heater and suspending the heater through one or more extensions between the inner sidewall of the structural housing and the heater.

6. The evaporator according to any one of claims 1-4, further comprising a structural housing, wherein the heater, the oven chamber, and the controller are housed within the structural housing; in, At least one inner passage is formed between the oven chamber and the nozzle, between the outer wall of the structural housing and the inner wall of the outer shell, and extends along the length of the outer wall of the structural housing and the inner wall of the outer shell; The at least one inner passage forms at least one cooling channel for the heated air and evaporated material to travel to the nozzle.

7. The evaporator according to any one of claims 1-6, wherein, The heater includes an elongated tube that includes recessed regions at at least some points along its length.

8. An evaporator, comprising: An evaporator body, comprising an outer shell and an internal structural housing housed within the outer shell and defining a cavity; An air inlet extends through a portion of the outer shell and into the cavity of the inner structural housing, through which air enters the cavity; A heater, suspended within the cavity of the internal structure housing, the heater having one or more openings through which air passes, the heater and the multiple openings generating turbulence in the air when the air passes over and through the heater for heating; An oven chamber, located within the cavity of the internal structural housing and holding an evaporable material therein, is heated by air heated by the heater, causing the evaporable material to evaporate into the heated air; A controller, coupled to the heater and configured to heat the heater to a predetermined temperature when airflow to the heater is detected; as well as The nozzle is configured to deliver the heated air and the evaporated material.

9. A method comprising: The suction at the nozzle of the sensor evaporator; Energy is applied to the heater of the evaporator; Monitor the air temperature of the heated air from the heater; The oven temperature of the evaporator's oven chamber is limited by changing the energy applied to the heater; and The heater temperature is adjusted in response to changes in the resistance of the heater to control the heater temperature.

10. An evaporator, comprising: Evaporator body, which includes an outer casing; A heater located within the evaporator body, the heater being configured to interfere with and heat the air flowing in the region of the heater; An oven chamber, fluidly coupled to the heater, holding an evaporable material within the oven chamber, the oven chamber configured to be heated by air heated by the heater, causing the evaporable material to evaporate into the heated air; and The nozzle is configured to deliver the heated air and the evaporated material.

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