Steam Supply Device

Abstract

Preventing or at least reducing the extent of leakage in and / or from electronic vapor delivery systems. The vapor delivery device (100) includes a main airflow passage (180) therein from an air inlet (170) to an air outlet (118), and air is drawn downstream from the air inlet (170) through the main airflow passage (180) to the air outlet (118) by a user's inhalation. The device (100) further includes a vaporizer (135) disposed within or adjacent to the main airflow passage (180) for supplying vapor to the main airflow passage (180), and a trap disposed in the main airflow passage (180) to retain liquid and thereby inhibit the flow of liquid along the main airflow passage in an upstream direction from the trap.

Description

[Technical Field]

[0001] The present disclosure relates to vapor delivery devices, such as nicotine delivery systems and electronic cigarettes. [Background technology]

[0002] Electronic vapor delivery systems, such as electronic cigarettes (e-cigarettes), generally include a reservoir of vapor precursor. The vapor precursor may be supplied as a liquid containing a formulation, typically including nicotine, from which vapor is generated for inhalation by a user. In other types of vapor delivery systems, sometimes referred to as hybrid devices, tobacco or other flavoring elements may be supplied separately from the vapor precursor.

[0003] Vapor delivery systems typically include a vaporizer, e.g., a vapor-generating chamber including a heating element, configured to vaporize a portion of the precursor. When a user draws on the mouthpiece of the e-cigarette and power is supplied to the vaporizer, air is drawn into the e-cigarette through an inlet hole and flows along a passageway into the vapor-generating chamber, where it mixes with vapor generated by the vaporizer to form an aerosol. The air drawn through the vapor-generating chamber continues along a passageway to the mouthpiece, carrying the vapor, and exits through the mouthpiece for inhalation by the user.

[0004] Electronic cigarettes that use liquid vapor precursors (e-liquids) present a risk of liquid leaking from the device. For example, many liquid-based e-cigarettes have a capillary wick for transporting the liquid (vapor precursor) from a reservoir to a vaporizer. Liquid can leak from the junction or interface between the wick and the liquid reservoir and / or from the wick itself. Liquid can also form when vapor condenses while still within the e-cigarette. Such liquid can scratch or damage components in the e-cigarette, for example, by corroding the components or affecting electrical operation within the device. In other cases, liquid can accumulate in certain locations within the e-cigarette, interfering with the device's ability to operate as intended. Furthermore, liquid can leak from the e-cigarette through the mouthpiece and / or any other openings (such as the air inlet hole). This leakage can be perceived as a quality defect by the user, and it is generally undesirable for liquid to come into contact with the user's skin or clothing. It would therefore be advantageous to prevent, or at least reduce the extent of, such leakage in and / or from electronic vapor delivery systems. Summary of the Invention

[0005] The invention is defined in the appended claims.

[0006] The vapor delivery device disclosed herein includes a main airflow passageway within the vapor delivery device from an air inlet to an air outlet, and air is drawn downstream from the air inlet through the main airflow passageway to the air outlet by a user's inhalation. The device further includes a vaporizer for supplying vapor to the main airflow passageway, the vaporizer being positioned within or adjacent to the main airflow passageway, and a trap positioned in the main airflow passageway to retain liquid and thereby inhibit the flow of liquid along the main airflow passageway in an upstream direction from the trap.

[0007] Also provided is a non-therapeutic method of operating a vapor delivery device, comprising the steps of providing a main air flow passage within the vapor delivery device from an air inlet to an air outlet; drawing air downstream from the air inlet through the main air flow passage to the air outlet by inhalation by a user; supplying vapor to the main air flow passage; and retaining liquid in a trap positioned in the main air flow passage to inhibit flow of liquid along the main air flow passage in an upstream direction from the trap. [Brief explanation of the drawings]

[0008] Various exemplary implementations of the techniques disclosed herein will now be described, by way of example only, with reference to the accompanying drawings, in which: [Figure 1] 1 is a schematic cross-sectional view of a vapor delivery device according to an embodiment of the present disclosure. [Figure 2] 2 is a schematic cross-sectional view of a portion of a vapor delivery device similar to that shown in FIG. 1 and including a tortuous air passageway. [Figure 3] 2 is a schematic cross-sectional view of a portion of another vapor delivery device similar to that shown in FIG. 1 and including a tortuous air passageway. [Figure 4] 2 is a schematic cross-sectional view of a portion of another vapor delivery device similar to that shown in FIG. 1 and including a tortuous air passageway. [Figure 5] 2 is a schematic cross-sectional view of a portion of another vapor delivery device similar to that shown in FIG. 1 and including a tortuous air passageway. [Figure 6] 2 is a schematic cross-sectional view of a portion of another vapor delivery device similar to that shown in FIG. 1 and including a labyrinth of air passages and a recess or depression that acts as a reservoir. [Figure 7] 2 is a schematic cross-sectional view of a portion of another vapor delivery device similar to that shown in FIG. 1 and including a recess or depression that acts as a reservoir. [Figure 8] 2 is a schematic cross-sectional view of a portion of another vapor delivery device similar to that shown in FIG. 1 and including a labyrinth of air passages and a recess or depression to act as a reservoir. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present disclosure relates to vapor delivery devices, also known as aerosol delivery systems, e-cigarettes, and vapor delivery systems. In the following description, the terms "e-cigarette" and "electronic cigarette" are generally used interchangeably with (electronic) vapor delivery systems / devices unless otherwise clear from the context. Similarly, the terms "vapor" and "aerosol," as well as related terms such as "vaporize," "volatilize," and "aerosolize," are generally used interchangeably unless otherwise clear from the context.

[0010] Vapor delivery systems (e-cigarettes) often have a modular design, including, for example, a reusable module (control unit or device unit) and a replaceable (disposable) cartridge module. The replaceable cartridge portion typically includes a vapor precursor and a vaporizer (and is therefore sometimes called a cartomizer), while the reusable module typically includes a power source, such as a rechargeable battery, and control circuitry. It will be understood that these modules may include additional elements depending on their function. For example, the reusable control portion may include a user interface for receiving user input and displaying operating status characteristics, and the replaceable cartridge portion may include a temperature sensor for use in helping to control temperature. In operation, the cartridge is typically electrically and mechanically coupled (removably) to the control unit using (for example) screws, latches, or bayonet fasteners, with electrical contacts appropriately engaged. When the vapor precursor in the cartridge is used up, or when the user wants to change to a different cartridge (perhaps with a different vapor precursor or flavoring), the cartridge can be removed (dismounted) from the control unit and a replacement cartridge installed instead. Devices that follow this type of two-part modular configuration are sometimes referred to as two-part devices.

[0011] Many of the examples described herein comprise two-part devices that use disposable cartridges and have an elongated shape. However, it will be understood that some e-cigarettes may have more modules, such as separate modules for the vapor precursor reservoir and vaporizer, while some e-cigarettes may be a single, integrated system. The approaches described herein can generally be incorporated into a wide range of electronic cigarette configurations, including one-part devices and modular devices with two or more parts, refillable devices, single-use disposable devices, and devices that follow a variety of overall shapes, including so-called box-mod high-performance devices that are typically more box-like (rather than elongated).

[0012] FIG. 1 is a cross-sectional view of an example e-cigarette 100. The e-cigarette 100 comprises two main components or modules: a reusable / control unit 101 and a replaceable / disposable cartridge 102. In normal use, the reusable part 101 and the cartridge 102 are removably coupled to each other at an interface 105. When the cartridge 101 is depleted, or when the user wishes to change to a different cartridge, the cartridge 102 can be removed from the reusable part 101 and a replacement cartridge 102 can be attached to the reusable part 101 instead. The interface 105 generally provides a structural and electrical connection between the two parts 101, 102, connecting the air passages and may use a latching mechanism, a bayonet fastener, or any other form of mechanical coupling as appropriate. The interface 105 also typically provides an electrical coupling between the two parts, which may be wired using a connector or wireless, for example, based on induction.

[0013] In FIG. 1 , cartridge 102 includes a reservoir 110 for containing a liquid vapor precursor (e.g., e-liquid) and further includes a chamber or container 120 for holding a solid material. In particular, liquid container (reservoir) 110 is formed within a first portion 115 of an outer shell or housing, and solid material container 120 is formed within a second portion 125 of the outer shell or housing. Outer shell 125 is further configured as a mouthpiece and provides an air outlet 118. Liquid container housing 115 and solid material container housing 125 may be provided as a single, integral component directly formed as a single unit during manufacture, or may be formed from two portions 115, 125 and then assembled substantially permanently together during manufacture. For example, liquid container housing 115 and material container housing 125 may be secured to one another along joint 122 by friction welding, spin welding, ultrasonic welding, or the like (or any other suitable technique). Cartridge housings 115 and 125 may be formed from plastic. It will be understood that the particular shapes of housings 115 and 125, along with their materials, sizes, etc., may vary according to the particular design of a given embodiment. In some embodiments, a user may separate outer shell 125 containing solid material container 120 from the remainder of housing 115 and cartridge 102, for example, to provide a new solid material container 120 containing new tobacco or other material.

[0014] The cartridge 102 is configured so that liquid from the reservoir 110 is vaporized to produce a vapor or aerosol, and then at least a portion (if not all) of the aerosol / vapor passes through the solid material in the container 120 to receive (entrain) the flavoring from the solid material. It will be appreciated that the solid material is therefore at least somewhat breathable, for example, the solid material may be in granular form, such as a powder, allowing air and vapor to pass through the spaces between the granules.

[0015] The liquid reservoir 110 of the cartridge 102 has an outer wall provided by the cartridge housing 115 and an inner wall 112 that also defines the outside of an air flow passage (air flow channel) 130 that extends along the central axis of the device (parallel to the main longitudinal axis through the cartridge 102). The liquid reservoir 110 therefore has an annular shape, such that liquid surrounds the air flow channel 130 that passes through the liquid reservoir 110. In other embodiments, the reservoir's inner wall 112 may extend only partially around the air flow channel 130 before engaging the cartridge housing 115, such that at least a portion of the air flow channel 130 is defined by the cartridge housing 115. The liquid reservoir 110 is closed at each end by the cartridge housing 115 to retain the e-liquid within the liquid reservoir.

[0016] The cartridge 102 includes a heater 135 for heating and thus vaporizing the liquid from the reservoir 110. The heater 135 may be, for example, an electric resistance heater, a ceramic heater, an induction heater, or any other suitable such device. FIG. 1 shows the heater 135 embodied as a resistive coil electric heater. The cartridge further includes a wick 140 that transfers the e-liquid from the reservoir 110 to the heater 135 for vaporization. As shown in FIG. 1, the heater 135 is wrapped (coiled) around the wick 140 to provide good thermal contact between the heater 135 and the wick. The wick 140 is generally absorbent and acts to draw liquid from the liquid reservoir 110 by capillary action. The wick 140 may be made of any suitable material, such as cotton or wool, synthetic materials including, for example, polyester, nylon, viscose, polypropylene, or the like, or ceramic or glass materials.

[0017] The wick 140 may be inserted into the reservoir 110 through one or more holes 145 in the interior wall 112 of the liquid container so that the wick 140 can contact the liquid in the reservoir 110. In other cases, the interior wall 112 may include at least one porous member, such as a ceramic disk (not shown), instead of holes 145. The at least one porous member contacts the wick 140, allowing liquid to pass through the interior wall 112 from the reservoir 110 to the wick 140. The wick then transports the liquid toward the heater 135 for vaporization. In the configuration shown in FIG. 1 , each end of the wick passes through the interior wall 112 into the reservoir 110. This configuration helps the interior wall 112 support the wick, thus holding it in place within the airflow channel. Additionally (or alternatively), the wick 140 may be at least partially supported by the heater coil 135. Other configurations will be apparent to those skilled in the art.

[0018] In use, cartridge 102 is attached to reusable portion 101, allowing heater 135 to receive power via wires 137 connected to reusable portion 101 across interface 105. Interface 105 includes electrical contacts or connectors, not shown in FIG. 1 , that connect wires 137 on cartridge 102 with corresponding wires on reusable portion 101 (generally, the wiring in FIG. 1 is shown only in schematic form, rather than showing detailed routing of such wiring, if present). Device 100 may be activated by a user drawing on mouthpiece 118, whereby puff detector 160 (airflow sensor) detects the airflow or pressure change resulting from the inhalation. Other types of devices may additionally or alternatively be activated by a user pressing a button or similar on the outside of the device. In response to a puff (inhalation) detected by puff detector 160, reusable portion 101 provides power to activate heater 135, causing liquid in wick 140 to volatilize or vaporize. The vapor or aerosol thus formed in the airflow channel 130 is drawn by the user's inhalation into and through the solid material container 120, where it picks up flavoring from the material in the container 120, before exiting through the mouthpiece 118 for inhalation by the user.

[0019] As liquid is vaporized from the wick 140, capillary action draws additional liquid from the reservoir 110 into the wick. The rate at which liquid is vaporized by the vaporizer (heater) 135 generally depends on the power level supplied to the heater 135. In some devices, the vapor production rate (vaporization rate) can be varied by a suitable control interface that varies the amount of power supplied to the heater 135 during operation. Adjusting the power level supplied to the heater 135 from the reusable part can be performed using pulse width modulation or any other suitable control technique.

[0020] The solid material container 120 is connected to the airflow channel 130 by a first end wall 117 and (at the mouth end) a second end wall 127. Each end wall 117, 127 is designed to retain the solid material within the container 120 while allowing airflow along the channel 130 and out through the mouthpiece 118. This may be achieved, for example, by end walls having appropriate pores that retain granules (or the like) of the solid material within the container 120 but allow air to flow through. The end walls 127 of the material container 120 may be provided by separate retainers, for example in the form of disks, inserted into each end of the housing 125 during manufacture. Alternatively, one or both of the end walls 117, 127 may be formed directly as part of the material container 120.

[0021] The reusable portion 101 includes a housing 165 having an opening defining one or more air inlets 170 for the e-cigarettes, a battery 177 for providing operating power to the device, control circuitry 175, user input buttons 150, a visual display 173, and a puff detector 160. In the configuration shown in FIG. 1 , the battery 177 and control circuitry 175 have a generally planar shape, with the battery 177 located below the control circuitry. The housing 165 may be formed, for example, from a plastic or metal material and has a cross-section that generally matches the shape and size of the cartridge portion 102, ensuring a smooth exterior transition between the two portions at the interface 105. The battery 177 is rechargeable and can be charged through a USB connector (not shown in FIG. 1 ) on the reusable portion housing 165.

[0022] The user input button 150 may be embodied in any suitable manner, e.g., as a mechanical button, a touch-sensitive button, or the like, to allow various forms of user input. For example, the user may use the input button 150 to turn the device on and off (whereby puff detection for activating the heater is only available when the device is turned on). The user input button 150 may also be used to set control settings, such as adjusting the power level. The display 173 visually indicates to the user various characteristics associated with the e-cigarette, such as the current power level setting, remaining battery power, on / off status, etc. The display may be embodied in various ways, e.g., using one or more light emitting diodes (LEDs) (possibly multicolored) and / or a small liquid crystal display (LCD) screen. Some e-cigarettes may also provide other forms of information to the user, e.g., using audio signals and / or tactile feedback.

[0023] Control circuitry 175 typically includes a processor or microcontroller (or the like) programmed or otherwise configured to control the operation of electronic cigarette 100. For example, in response to puff detection from puff detector 160, control circuitry 175 provides power from battery 177 over line 137 to heater / vaporizer 135 to generate vapor for a user's inhalation. Control circuitry can also monitor additional conditions within the device, such as battery power level, and provide a corresponding output via display 173.

[0024] In the e-cigarette 100 shown in FIG. 1 , the air inlet 170 connects to an airflow passage 172 through the reusable portion 101. When the reusable portion 101 and cartridge portion 102 are connected together, the air passage 172 of the reusable portion 101 connects to the cartridge via interface 105 and thus to the airflow channel 130. A puff detector (sensor) 160 is located within or adjacent to the airflow passage 172 of the reusable portion 101 to notify the control circuitry 175 when a user draws on the device 100. The combination of the air inlet 170, airflow passage 172, airflow channel 130, and mouthpiece 118 can be considered to form or represent the primary airflow passage of the e-cigarette 100, whereby airflow resulting from a user's draw travels from the air inlet 170 (upstream) to the mouthpiece 118 (downstream) in the direction indicated by the arrows in FIG. 1 .

[0025] In some devices, for example, leakage may occur from the wick 140 and / or reservoir 110 (and / or from joints between the two, such as holes 145). Another potential source of leakage is vapor generated by the heater 135 recondensing in the airflow channel 130 rather than exiting the e-cigarette in vapor form through the mouthpiece 118. A puff detector 160 located in the main airflow path through the device may be susceptible to damage or impaired operation from contact with such leaked e-liquid. For example, leaked liquid may travel along the main airflow path (upstream, i.e., opposite the direction of normal airflow as the user draws) and cause corrosion or other damage to external and / or internal components of the puff detector 160 (including, for example, wires connecting the puff sensor 160 to the control circuit 175). Another possibility is that liquid may accumulate on the surface of the puff sensor 160, which may form a layer over the surface of the puff sensor, thereby isolating it from the airflow passage 172. As a result, the puff detector 160 may become less sensitive to changes in airflow, and therefore it may become more difficult (if not impossible) to activate the e-cigarette by drawing on it.

[0026] In addition to, or instead of, interfering with the operation of the puff detector 160 as described above, leaking liquid may cause other problems for the e-cigarette. For example, liquid may leak from the e-cigarette, such as from the mouthpiece 118, from the air inlet 170, and / or at the interface 105 between the cartridge 102 and the control unit 101 (particularly when the cartridge 102 and the control unit 101 are separated, such as for replacing the cartridge). Besides creating the impression of poor manufacturing quality, such leakage may (depending on the particular formulation of the e-liquid) cause discomfort or irritation to the user's skin and / or stain clothing.

[0027] Accordingly, the e-cigarette 100 or vapor device described herein includes certain features to attempt to contain or limit the movement of liquid that may leak into (or form within) the airflow channel 130. For example, the airflow channel 130 includes a section of a tortuous passageway 180 disposed between the airflow sensor 160 and the vaporizer 135. This tortuous passageway is part of the device's main airflow path and typically includes at least two bends, each bend having an angle of 90 degrees or greater. The tortuous air passageway 180 shown in FIG. 1 ensures that there is no simple, direct path (e.g., line of sight) between (i) the puff sensor 160 and (ii) the vaporizer 135 and wick 140 (and wick opening 145 in the interior wall 112).

[0028] The main airflow passage may also include a reservoir (liquid reservoir or recess) 179. The reservoir 179 helps to retain liquid that leaks from the wick 140 or related components and travels upstream (opposite the direction of airflow) along the main airflow passage. It will be appreciated that in normal use, the tip is generally held in an upward position relative to the rest of the e-cigarette 100, and therefore any liquid that leaks from the wick 140 or reservoir 110 (or liquid that condenses downstream of the vaporizer) will tend to flow or fall by gravity down the airflow channel 130 toward the reservoir 179. This liquid then collects in the reservoir 179, which acts as a form of liquid trap, thereby helping to prevent the liquid from flowing further down the airflow channel 130 toward the puff sensor 160. As will be explained in more detail below, the tortuous passage 180 can also be thought of as a form of trap to prevent or inhibit liquid from flowing further down the airflow channel 130 towards the puff sensor 160.

[0029] 2-8 provide further examples of devices that include a convoluted portion 180 and / or a reservoir 179 as a trap for the main airflow channel. It will be appreciated that these various example designs may be implemented as appropriate in the electronic cigarette of FIG. 1 or any other e-cigarette or vapor delivery device where leakage may potentially be a concern.

[0030] In particular, Figures 2-8 schematically illustrate a cross section of a portion of an electronic cigarette or vapor delivery device 100, such as that shown in Figure 1. The illustrated portion includes the section of the main airflow path from the puff sensor 160 to (slightly past) the wick 140 and heater 135. Note that the illustrated portion depicted in Figures 2-8 generally corresponds to the portion identified by the dashed box marked A in Figure 1. Thus, this portion of the electronic cigarette 100 includes the cartridge housing 115, the control housing 165, and at least a portion of the liquid reservoir 110, as well as the wick 140 and the vaporizer (heating coil) 135. The illustrated portion of the electronic cigarette further includes a portion of the interior wall 112 of the liquid reservoir 110 having one or more openings 145 through which the wick 140 couples to the liquid reservoir 110. The illustrated sections of the electronic cigarettes shown in Figures 2-8 further include portions of the main airflow passageway that run in the direction indicated by the arrows from the air inlet 170 to the mouthpiece, which serves as the air outlet 118 (the air inlet 170 and air outlet 118 are not shown in Figures 2-8). Note that these airflow arrows in Figures 2-8 can be considered to represent the primary, normal (e.g., average), or net airflow direction at the indicated location.

[0031] 2-8, a heater 135 is disposed in the main airflow passage and is coupled to the liquid reservoir 110 by a wick 140 such that the heater 135 can vaporize liquid from the reservoir 110. An airflow sensor (puff detector) 160 is also disposed in the main airflow passage upstream of the heater 135 to detect a user's draw on the tip in order to activate the heater. In the illustrated example, the shape of the main airflow passage is defined primarily by the reusable portion housing 165, the cartridge portion housing 115, and the inner wall 112 of the liquid reservoir 110. However, e-cigarettes may optionally utilize other components or structures to define a suitable main airflow passage according to the requirements of any given embodiment.

[0032] Referring now to the particular configuration of Figure 2, the main airflow path from the airflow sensor (puff detector) 160 to the heater (vaporizer) 135 comprises a convoluted section 180 that includes first and second bends 181, 182. If the top of the mouthpiece is represented as the top of the entire e-cigarette 100, the airflow shown in Figure 2 travels upward from the puff detector 160 (i.e., flows toward the top) before making an approximately 90-degree turn at the first bend 181 and flowing sideways (inward toward the center of the device). The airflow then makes another approximately 90-degree turn at the second bend 182, returning to its original upward flow direction along the airflow channel 130. In other words, the change in direction or rotation of the second bend 182 is in the opposite direction to the change in direction or rotation of the first bend 181, so that they are seen to cancel each other out, i.e., the original direction of airflow as it enters the convoluted portion 180 is maintained relative to the direction of airflow as it exits the convoluted portion (although the exiting airflow is slightly offset laterally towards the center of the device compared to the incoming airflow).

[0033] Thus, the main airflow passage can be thought of as extending in a first direction (vector) from airflow sensor 160 to first bend 181, in a second direction (vector) between first bend 181 and second bend 182, and in a third direction (vector) from second bend 182 toward carburetor 135. These directions represent the downstream direction of the (average or net) airflow in the corresponding section of the main airflow passage. The first and third directions are parallel to each other, while the second direction is perpendicular to the first and third directions. The airflows in the first and third directions are parallel but laterally offset from each other (by an amount corresponding to the distance traveled by the airflow in the second direction).

[0034] The first and second bends 181, 182 form a tortuous passage 180 in the main airflow passageway, which acts as a form of trap, preventing liquid from migrating upstream of the trap (tortuous passage 180) toward the puff detector 160. In particular, air moves effortlessly downstream from the puff detector 160 through the tortuous passage 180 to the vaporizer 135 due to the pressure differential between the air inlet 172 (generally atmospheric pressure) and the mouthpiece 118 (which is below atmospheric pressure due to the user's draw). In contrast, any liquid within the device tends to move (fall) under the influence of gravity, as the weight of the liquid generally overcomes the pressure differential resulting from the user's draw. In the normal orientation of the e-cigarette during use, with the mouthpiece 118 at the top, this gravitational effect causes any free liquid to move in the opposite direction to the air, i.e., the liquid tends to fall upstream from the vaporizer 135 toward the puff detector 160. The tortuous passageway 180 acts to impede this gravity-driven movement of the liquid. For example, the portion of the tortuous passageway 180 between the first and second bends 181, 182 in FIG. 2 is generally horizontal, and therefore acts as a barrier or retardant (or trap) to such gravity-driven movement along the main airflow channel. This tortuous passageway 180 therefore helps to reduce the risk (or amount of liquid) of liquid from the vaporizer reaching and potentially damaging the puff sensor 160. Similarly, the tortuous passageway 180 also helps to reduce the risk (or amount of liquid) of liquid exiting the e-cigarette at the air inlet 170. Furthermore, because the tortuous passageway 180 is positioned downstream (in the direction of air flow) of the interface 105, the tortuous passageway 180 also helps to reduce the risk (or the amount of liquid) of liquid exiting the e-cigarette at the interface 105 (particularly when the reusable part 101 is removed from the cartridge 102).

[0035] While each of the first and second bends 181, 182 is shown in FIG. 2 as a sharp (right-angled) corner, it will be understood that either or both of these bends may be embodied as curved, rounded, or with an overall more gradual change in direction. Furthermore, while the first and second bends 181, 182 are shown in FIG. 2 as being separated by a short section of cross flow, in other embodiments, the first and second bends 181, 182 may be directly connected to one another and may change direction sequentially, for example, first in one direction and then in the opposite direction. Alternatively, in some embodiments, additional bends or changes in direction may be disposed between bends 181, 182.

[0036] Referring now to Figure 3, which also schematically illustrates a cross section of a portion of an electronic cigarette. Many aspects of Figure 3 are the same as the corresponding aspects of Figure 2 and, therefore, for the sake of brevity, will not be described again in detail. However, while in the example of Figure 2 the first and second bends each bend at an angle of approximately 90 degrees, in the example of Figure 3 both first and second bends 181 and 182 bend at an angle of approximately 180 degrees.

[0037] As in Figure 2, the bend angles of the first and second bends 181, 182 in Figure 3 are equal in magnitude but opposite in rotation. In other words, the bend angle of the first bend 181 is the opposite of the bend angle of the second bend 182, so that the first direction (into the convoluted portion 180, as defined above) is parallel to the third direction (out of the convoluted portion 180, as defined above). Furthermore, because both the first and second bends 181, 182 bend at 180-degree angles, the second direction (between the first and second bends) is (approximately) antiparallel to the third direction and the first direction (by antiparallel, we mean that the second direction is parallel to but opposite the first and third directions). As in Figure 2, the direction of the third air flow is slightly laterally offset (generally towards the center of the device) compared to the direction of the first air flow, the amount of offset being determined by the size and spacing of the first and second bends 181, 182.

[0038] Note that in the embodiment of FIG. 3 , the first and second bends are coplanar. In other words, if first bend 181 is considered a 180-degree rotation about a first axis and second bend 182 is considered a 180-degree rotation about a second axis, then the first and second axes are parallel (both perpendicular to the plane of the page in FIG. 3 ). However, bends 181, 182 do not have to be coplanar; for example, the first and second axes may be perpendicular to each other (yet both perpendicular to the upward direction of the device). In other cases, the angle between the two axes may be an intermediate angle (greater than 0 degrees and less than 90 degrees). In some cases, individual bends may not be planar and may have more complex curvatures, for example, involving various degrees of rotation about various axes.

[0039] The convoluted passage 180 of FIG. 3 (compared to the convoluted passage 180 shown in FIG. 2) provides a greater impediment to liquid migration upstream of the vaporizer 135. Here, the first and second bends 181, 182 shown in FIG. 3 define a small wall or barrier (or lip) 384 that prevents horizontal flow of liquid that might occur in the configuration of FIG. 2. Thus, to pass upstream through the convoluted portion 180, any liquid must travel upward a certain distance to overcome the wall or barrier 384. It will be appreciated that gravity generally prevents liquid from overcoming the wall 384, at least while the e-cigarette 100 is held in its normal orientation for use. Furthermore, the leakage protection provided by the configuration of FIG. 3 (compared to the configuration of FIG. 2) is more robust because slight changes in the orientation of the device shown in FIG. 3 are generally ineffective in causing liquid to overcome the wall 384. Thus, even if there is some movement of the e-cigarette, for example, rotation or tilting, the design of Figure 3 still prevents upstream movement of liquid.

[0040] Additionally, the wall 384 can also be thought of as providing a trap or reservoir 179 located at or near the bottom of the air flow channel 130. Thus, at least while the device is held in a relatively normal orientation, any leaked liquid can collect and remain in the trap or reservoir 179. This further helps prevent any leaked liquid from potentially damaging internal components of the e-cigarette and / or from exiting the e-cigarette in an undesired manner.

[0041] In the example of FIG. 3, the second direction is antiparallel to the first and third directions. However, other embodiments may have different configurations. For example, reference is now made to FIG. 4, which also schematically illustrates a cross-section of a portion of an electronic cigarette. Various aspects of the e-cigarette of FIG. 4 are the same as or similar to the corresponding aspects of FIG. 2 (and / or FIG. 3) and, therefore, for the sake of brevity, will not be described again in detail. However, while in the example of FIG. 2, the first and second bends 181, 182 are both bent at an angle of approximately 90 degrees, and in the example of FIG. 3, the first and second bends 181, 182 are both bent at an angle of approximately 180 degrees, the embodiment of FIG. 4 illustrates that these various directions need not be parallel (or antiparallel), and the first and second bends may be bent at different angles. For example, in FIG. 4, the second bend 182 bends at an angle of approximately 180 degrees, while the first bend 181 bends (in the opposite direction) at a smaller angle of approximately 160 degrees.

[0042] Furthermore, while the third airflow direction in Figure 4 is generally parallel to the device's main airflow direction (as indicated in Figure 4 by the arrows along the airflow channel 130), and the second airflow direction between the first and second bends 181, 182 is generally anti-parallel to this third direction, the first airflow direction, i.e., the airflow direction upstream of the first bend 181, is tilted (not parallel) at an angle of about 20 degrees relative to both the second and third airflow directions. For example, this tilted direction may be employed to help other components fit more easily within the e-cigarette. While Figure 4 shows the first direction as tilted relative to the vertical (of the device's normal orientation), it will be understood that in other embodiments, the second and / or third directions may also (or alternatively) be similarly tilted.

[0043] Note that in FIG. 4 , the first direction is still generally upward (toward the tip), as is the third direction, while the second direction is generally downward (away from the tip). This can be semi-quantified based on the fact that the third airflow direction has a positive dot product with the first airflow direction, while the second airflow direction has a negative dot product with the first airflow direction and similarly with the third airflow direction. It can thus be seen that the second airflow direction has a negative or opposite component with respect to the first and third airflow directions, which leads to the presence of a lip or rim 384 between the first and second bends 181, 182. As discussed above with respect to FIG. 3 , this rim or wall 384 can be thought of as providing a reservoir or trap 179 located at or near the bottom of the airflow channel 130. The rim 384 provides a gravitational barrier to such liquids migrating further upstream, so that any leaking liquid can collect and remain in a reservoir or trap, at least while the device is held in its normal orientation.

[0044] Referring now to Figure 5, this also schematically illustrates a cross section of a portion of an electronic cigarette. Many aspects of Figure 5 are the same as those of the corresponding Figures 2, 3, and / or 4 and therefore, for the sake of brevity, will not be described again in detail. In the example of Figure 5, the convoluted passageway 180 is effectively formed by two tubes, a first tube 585 and a second tube 586. The first tube 585 extends from the puff detector 160 in the direction of the first airflow upward (toward the mouthpiece) and into the second tube 586. A first bend 181 is located at the open end (top) of the first tube 585.

[0045] A second tube 586 extends in the direction of a second, opposite downward airflow (away from the mouthpiece) and surrounds the first tube 586, creating an annular space radially outward of the first tube 585 but inside the second tube 586. The second tube is closed at the top, thereby effectively creating the first bend 181, and open at the bottom. After passing through the first bend 181, the airflow flows downward through the annular space in a second airflow direction that is antiparallel to the first airflow direction before reaching the lower, open end of the second tube 586. The air flow then passes (bends) through a second bend 182 and flows in a third air flow direction that is generally parallel to the first air flow direction (although FIG. 5 shows the first and third air flow directions to be substantially parallel to each other, similar to the configuration of FIG. 3, it will be understood that the first and third air flow directions may be angled relative to each other, similar to the configuration of FIG. 4).

[0046] 5, the airflow travels twice along the first tube 585. Note that the first time, it travels internally inside the first tube 585, and the second time, after reaching the first bend 181 at the end of the first tube 585, it travels in the opposite direction, externally in the space outside the first tube 585 (but is held within this space by the second tube 586). The first tube 585 thus forms a gravity barrier to liquid returning from the air passageway 130 towards the puff detector 160. The first tube 586 is thus somewhat analogous to the rim 384 as shown in the embodiments of FIGS. 3 and 4, and thus can similarly be thought of as providing or defining the reservoir area 179.

[0047] One advantage of the configuration of Figure 5 (e.g., compared to the configuration of Figure 3) is that it helps to increase the robustness against leakage even when there is movement of the e-cigarette. For example, in the configuration of Figure 3, if the device is rotated about a horizontal axis perpendicular to the plane of the figure (i.e., into the page), with the first rotation being 180 degrees clockwise, followed by a second rotation 180 degrees counterclockwise, this will generally cause liquid to flow (leak) from the reservoir 179, through the convoluted portion 180, and towards the puff detector 160. In contrast, when the configuration of Figure 5 undergoes the same movement, the liquid will generally flow into the second tube 586 for the first rotation, but for the second rotation, the liquid will generally return outside the first tube 585, i.e., back to the bottom of the air passage 130 and the trap 179.

[0048] 5, and in particular the convoluted portion 180 comprising the overlapping first and second tubes 585, 586, can be viewed as a form of valve with directional preference or asymmetry. In particular, in this configuration, it is more difficult for liquid to flow upstream than downstream (in contrast, the wall or rim 384 provides a potential energy barrier that can be considered symmetrical in the upstream and downstream directions). It can be seen that the asymmetry of FIG. 5 arises because, when moving downstream, the flow first passes through the inner (first) tube 585 and then the outer (second) tube 586, whereas, when moving upstream, the flow first passes through the outer tube 586 and then the inner tube.

[0049] It should be noted that the e-cigarette 100 situation differs from many valve implementations in that the configuration of Figure 5 must simultaneously prevent the upstream flow of liquid while maintaining the downstream flow of air in response to a user's draw. The configuration of Figure 5 can simultaneously achieve this, provided that the accumulated liquid does not become deep enough to block the ends of the first or second tubes. However, such blockage can generally be avoided by providing sufficient clearance at the respective ends of the first and second tubes, for example, to account for potential leakage rates within the device 100.

[0050] Referring now to FIG. 6, this also schematically illustrates a cross section of a portion of an electronic cigarette. Many aspects of FIG. 6 are the same as those of the corresponding FIGS. 2, 3, 4, and / or 5 and, therefore, for the sake of brevity, will not be described again in detail. In particular, the convoluted portion 180 of the air passageway (airflow channel) 130 shown in FIG. 6 is generally similar to the example of FIG. 2. However, unlike the example of FIG. 2, the embodiment of FIG. 6 includes a reservoir or trap 179 to help prevent leakage of liquid from the air passageway 130. Note that in the embodiment of FIG. 6, the reservoir is not formed with the convoluted portion 180 (e.g., by forming a rim or lip 384), but rather by forming a recess or depression 191 (or a depression of other form or shape) in the bottom or floor of the air passageway 130. This recess 191 serves to retain liquid that forms or travels upstream of the vaporizer 135, and is positioned such that, in normal use, when the e-cigarette is held in a standard orientation, gravity acts to retain the liquid within the recess 191 rather than allowing the liquid to travel further upstream. Thus, the recess 191 is formed in the surface of the air passage 130 that typically serves as the bottom or floor of the airflow channel during normal use. Accordingly, the placement of the recess 191 shown in FIG. 6 is merely exemplary, and the recess 191 could be moved, for example, to the left or right of the position shown in FIG. 6 . In some embodiments, the recess 191 may be positioned generally below the vaporizer 135 (in accordance with the device's normal orientation in use) to help increase the likelihood that any liquid leaking from the vaporizer 135 or wick 140 will fall or flow into the recess 191.

[0051] In some embodiments, reservoir 179 may comprise absorbent material 194 to help retain liquid in the recess. For example, during or after use, a user may tilt device 100 and turn it so that mouthpiece 118 is no longer at the top, thereby allowing liquid to flow out of recess 191 due to gravity. In these situations, the absorbent material prevents the liquid from freely flowing out of the reservoir, and may help retain at least some of the liquid in reservoir 179, for example, by osmotic pressure. The absorbent material may comprise a porous and / or hydrophilic material, such as a sponge or foam or the like.

[0052] Furthermore, the absorbent material can facilitate dissipation or evaporation of the liquid, for example, by increasing the effective liquid-air interface area. It will be appreciated that such dissipation helps to reduce leakage, firstly, because evaporated liquid frees up new storage volume within the absorbent material, and secondly, because once the liquid has evaporated, there is no longer any risk of such liquid leaking (as a liquid) from the absorbent material when, for example, the e-cigarette is subjected to sudden movement, such as being dropped.

[0053] By locating the absorbent material 194 in the reservoir 179, space can be used efficiently. Furthermore, such placement allows the absorbent material to help retain any liquid that may be present in the reservoir 179, even when the e-cigarette is tilted significantly (which could cause the liquid to spill out of the reservoir 179). However, in some embodiments, the absorbent material may be located in another location away from the reservoir 179 (and / or the convoluted portion 180).

[0054] The reservoir 179 may be designed to have a volumetric capacity of 2% to 50% of the volumetric capacity of the liquid reservoir 110, more typically 5% to 15%. For example, the liquid reservoir 110 may have a capacity of 2 ml, and the reservoir 179 may have a capacity of approximately 0.2 ml. This size of the reservoir reflects the fact that liquid will only gradually leave the reservoir, and that most of this liquid may be vaporized by the heater 135. Note also that the reservoir is intended to prevent (or reduce) leakage from or within the device. Liquid may gradually evaporate from the reservoir, and the resulting vapor may then escape from the device, for example, through the mouthpiece 118. However, this slow leakage of vapor from the device is generally not noticeable (or harmful) to the user. A particular absorbent material 194 (if used) may be able to hold a volume of water greater than its own volume. In some cases, the absorbent material may extend slightly above or out of the recess 191, effectively above the floor or bottom of the air flow channel 130, and still retain liquid. Absorbent material may also be used to retain or capture liquid without any reservoir or recess.

[0055] Referring now to FIG. 7, which also schematically illustrates a cross section of a portion of an electronic cigarette. Certain aspects of FIG. 7 are the same as those of the corresponding FIG. 6 embodiment and, therefore, for the sake of brevity, will not be described again in detail. In particular, the FIG. 7 embodiment includes a recess 191 to serve as a reservoir 179, as described above with respect to FIG. 6. However, the FIG. 7 embodiment does not include a section of a labyrinthine air passage (such as portion 180 of the FIG. 6 embodiment). In the FIG. 7 embodiment, reservoir 179 is disposed at the upstream end of airflow channel 130 to help retain liquid traveling upstream from the vaporizer. Reservoir 179 in FIG. 7 is again filled with an absorbent material to help retain such liquid.

[0056] Referring now to FIG. 8, this also schematically illustrates a cross section of a portion of an electronic cigarette. Certain aspects of FIG. 8 are the same as those of the corresponding FIGS. 1-7 and, therefore, for the sake of brevity, will not be described again in detail. In particular, the embodiment of FIG. 8 includes a tube 585 extending from the reusable portion to the cartridge or cartomizer portion across interface 105. The area of cartridge 587 surrounding tube 585 is suitably elastic to maintain a seal around tube 585, preventing unwanted liquid or vapor (or air) leakage. This tube forms part of main airflow channel 130 and helps define convoluted portion 180 as described above. Note that the particular configuration of FIG. 8 can also be thought of as acting as a valve for upstream liquid flow (while allowing downstream air movement), in a manner similar to the embodiment of FIG. 5. 8 further includes a reservoir 179 provided by a lip or barrier 384 formed by a tube 585 (part of the convoluted portion 180) along with the recess 191. Additionally, the recess 191 also includes an absorbent material 194.

[0057] Thus, Figure 8 illustrates how various components or elements can be combined to capture or retain liquid traveling upstream from the vaporizer. For example, the embodiment of Figure 8 can be thought of as providing a multi-component trap for liquid, with a first component acting as a gravitational (potential energy) barrier formed from both recess 191 and wall 384, a second component acting as a valve (as described above) formed by convoluted portion 180, and a third component comprising absorbent material 194.

[0058] It should be noted that these various components work in a complementary or synergistic manner. Thus, the first component (the gravity barrier) is generally very effective when the e-cigarette is held in a normal orientation. Meanwhile, the absorbent material 194 can help retain liquid through osmotic pressure or the like (such as hydrophilic attraction) regardless of orientation. Furthermore, the absorbent material can promote dissipation or evaporation of liquid, thereby helping to maintain the volume of the absorbent material and (in embodiments where the absorbent material is disposed in a reservoir) the volume of the reservoir 179. Furthermore, even if liquid escapes (leaks) through such absorbent material 194 in the configuration of FIG. 8, such liquid is still impeded by the valve formed by the inner tube 585, again, without requiring a normal (vertical) orientation to be effective. It can thus be seen that many such components support each other to help prevent or at least reduce leakage. Reducing leakage in this manner can be beneficial, for example, by helping to protect internal components and reducing the risk of any adverse user experience.

[0059] Thus, a vapor delivery device as disclosed herein comprises a main airflow passage within the vapor delivery device from an air inlet to an air outlet, with air being drawn downstream from the air inlet through the main airflow passage to the air outlet by a user's inhalation. The device further comprises a vaporizer for supplying vapor to the main airflow passage, the vaporizer being disposed within or adjacent to the main airflow passage, and a trap disposed in the main airflow passage upstream of the vaporizer to retain liquid by restricting the liquid from flowing along the main airflow passage in (at least) an upstream direction from the trap. (In some cases, the trap may also restrict flow in a downstream direction.)

[0060] The trap may be based on using some form of gravitational (potential energy) barrier which may be provided, for example, by a reservoir and / or a convoluted portion of the main airflow passage. The reservoir itself may be provided, for example, by a suitable depression or recess formed in a wall (e.g. the bottom) of the main airflow passage, and / or by a wall, rim, barrier, etc. (which may typically be formed as part of the convoluted portion).

[0061] Additionally or alternatively, the trap may use some form of absorbent material, such as a foam or sponge, to capture or retain liquid based on, for example, osmotic pressure, hydrophilicity, or the like. Absorbent material may also be disposed in the reservoir to provide additional retention capabilities. It will be appreciated that the better the liquid retention, the more reduced leakage can be expected. Furthermore, liquid retention is achieved without impeding or significantly reducing airflow through the device (which may impede or significantly reduce airflow through the device, which may impede or worsen the use of the device).

[0062] The traps described herein particularly help to retain liquids produced by or near the vaporizer, thereby preventing upstream migration of such liquids that could contaminate or disable (for example) the puff sensor. This is supported by locating the trap relatively close to the vaporizer, e.g., within line of sight and / or within a distance of, for example, 5, 10, or 15 mm.

[0063] In some embodiments, the convoluted portion may comprise first and second bends (the first bend being upstream of the second bend), a first flow section (between the first and second bends), and a second flow section (immediately downstream of the second bend). When the device is held in a normal orientation for inhalation by a user (typically with the mouthpiece at its highest point), the first flow section is higher than the second flow section. It will be appreciated that this height difference provides a positional barrier to help prevent or restrict the flow of liquid from the second section into the first section (i.e., upstream).

[0064] The use of such gravity barriers is at least partially dependent on the orientation of the device. One way to address this is to include a valve arrangement in the main airflow path that makes upstream flow more difficult than downstream flow. Another way to address this is to use an absorbent material to retain (or help retain) liquid, as the absorption of the material is effective regardless of orientation (but liquid retained by this material is still subject to gravity, of course).

[0065] Because this downstream passage must remain open to support the user's draw, the traps described herein have little or no effect on the downstream flow of air. One way to quantify this is based on the resistance to draw (RTD), which can be expressed as the differential pressure required to draw (suck) air through the e-cigarette at a given flow rate, e.g., 17.5 milliliters per second (see ISO 3402). The traps described herein generally alter the RTD (compared to an e-cigarette without a trap) by less than 20%, preferably 15%, preferably less than 10%, preferably less than 5%, and preferably less than 2%.

[0066] The techniques described herein can be used with vapor delivery devices that form a complete system, such as an e-cigarette, as well as with vapor delivery devices that form a portion or component of such a complete system, for example, in the latter situation the vapor delivery device may represent a cartridge or a cartomizer.

[0067] While the above embodiments illustrate specific exemplary vapor delivery systems and devices, it will be understood that the same principles disclosed herein can be applied to vapor delivery systems and devices using other technologies. For example, while FIG. 1 illustrates air inlet 170 and puff sensor 160 as components of reusable part 101, one or both of air inlet 170 and puff sensor 160 can be components of cartridge 102. Similarly, while the above embodiments primarily focus on vapor delivery systems and devices having a resistive heater coil as the vaporizer, in other examples, the vaporizer can include another form of heater, such as a planar heater in contact with the liquid transfer element. Furthermore, in other embodiments, the vaporizer can be inductively heated or can use other vaporization techniques (other than heating), such as piezoelectric stimulation to generate vapor. Furthermore, as noted, the above embodiments focus on vapor delivery systems including two-part devices. However, the same principles can be applied to other forms of aerosol or vapor delivery systems that do not rely on a replaceable cartridge, such as refillable or disposable devices. Additionally, although the above embodiment includes a solid material chamber 120, the techniques described herein can be used in devices that do not use solid materials in this manner.

[0068] In summary, to address various challenges and advance the art, this disclosure illustratively presents various embodiments in which the claimed invention(s) may be practiced. The advantages and features of the present disclosure are merely representative examples of embodiments and are not intended to be comprehensive and / or exclusive. They are presented merely to aid in the understanding and teaching of the claimed invention(s). The advantages, embodiments, examples, functions, features, structures, and / or other aspects of the present disclosure should not be construed as limiting the present disclosure as defined by the claims or the equivalents of the claims, and it should be understood that other embodiments may be utilized and modifications may be made without departing from the scope of the claims. It should be understood that features and aspects of the present disclosure described herein with respect to specific embodiments may be combined, as appropriate, with features and aspects of other embodiments, and not just in the specific combinations described above. It will be understood that various embodiments may suitably comprise, consist of, or consist essentially of various combinations of the disclosed elements, components, features, parts, steps, means, etc. other than those specifically described herein, and thus features of the dependent claims may be combined with features of the independent claims in combinations other than those explicitly set out in the claims. The present disclosure may include other inventions not currently claimed but which may be claimed in the future.

Claims

1. 1. A vapor delivery device comprising: a main air flow passage within the vapor delivery device from an air inlet to an air outlet, wherein air is drawn downstream from the air inlet through the main air flow passage to the air outlet by a user's inhalation; a vaporizer for supplying vapor to the main airflow passage, the vaporizer being located within or adjacent to the main airflow passage; a trap positioned in the primary airflow passage to retain liquid and thereby inhibit the flow of liquid along the primary airflow passage in an upstream direction from the trap; an airflow sensor for detecting a user's inhalation on the device; Equipped with the trap is located in the main airflow passage upstream of the carburetor and downstream of the airflow sensor; The trap is a convoluted portion of the main airflow passageway, the convoluted portion having at least first and second bends, each of the first and second bends bending the convoluted portion through an angle of at least about 90 degrees; the convoluted portion includes a valve arrangement to restrict upstream liquid flow through the convoluted portion relative to downstream liquid flow through the convoluted portion; the valve arrangement comprises a tube, and air flowing in a downstream direction first travels along the inside of the tube and then returns around the outside of the tube; Steam delivery device.

2. 2. The vapor delivery device of claim 1, wherein one or both of the first and second bends are bent at an angle greater than 90 degrees.

3. 3. The vapor delivery device of claim 1, wherein one or both of the first and second bends are bent at an angle of approximately 180 degrees.

4. 4. The vapor delivery device of claim 1, further comprising an airflow sensor disposed in or adjacent to the main airflow passage, wherein the main airflow passage has a first direction between the airflow sensor and the first bend, a second direction between the first bend and the second bend, and a third direction between the second bend and the vaporizer, the first direction and the third direction being substantially parallel to but offset from each other.

5. The vapor delivery device of claim 4 , wherein the second direction is at least partially opposite to the first direction.

6. 6. A vapour delivery device according to any preceding claim, wherein the convoluted portion provides a gravitational barrier to the flow of liquid in an upstream direction when the device is held in a normal orientation for inhalation by a user.

7. 7. The vapor delivery device of claim 6, wherein the convoluted portion comprises first and second sections, the first section being upstream of the second section, and further wherein the first section is higher than the second section when the device is held in a normal orientation for inhalation by a user.

8. 10. The vapor delivery device of claim 1, wherein the trap comprises a gravity barrier to inhibit upstream liquid flow when the device is held in a normal orientation for inhalation by a user.

9. 9. A vapor delivery device according to any one of claims 1 to 8, configured to contain or receive a reservoir of liquid to be vaporized, the trap having a capacity to hold between 2% and 30% of the volume of the reservoir, preferably between 5% and 15% of the volume of the reservoir.

10. A vapor delivery device according to any preceding claim, comprising a cartomizer for connection to a reusable component for powering the vapor delivery device.

11. A vapour delivery device according to any preceding claim, wherein the trap does not substantially affect the downstream flow of air resulting from a user's inhalation.

12. 1. A vapor delivery device comprising: a main air flow passage within the vapor delivery device from an air inlet to an air outlet, wherein air is drawn downstream from the air inlet through the main air flow passage to the air outlet by a user's inhalation; a trap positioned in the primary airflow passage to retain liquid and thereby inhibit the flow of liquid along the primary airflow passage in an upstream direction from the trap; an airflow sensor for detecting a user's inhalation on the device; Equipped with the trap is located in the main airflow passage upstream of the carburetor and downstream of the airflow sensor; The trap is a convoluted portion of the main airflow passageway, the convoluted portion having at least first and second bends, each of the first and second bends bending the convoluted portion through an angle of at least about 90 degrees; the convoluted portion includes a valve arrangement to restrict upstream liquid flow through the convoluted portion relative to downstream liquid flow through the convoluted portion; the valve arrangement comprises a tube, and air flowing in a downstream direction first travels along the inside of the tube and then returns around the outside of the tube; Steam delivery device.

13. A vapor delivery system comprising a vapor delivery device according to any one of claims 1 to 12 in combination with a power supply and control circuitry.

14. 1. A non-therapeutic method of operating a vapor delivery device, comprising: providing a main air flow passage within the vapor supply device from an air inlet to an air outlet; drawing air downstream from the air inlet through the main air flow passage to the air outlet by a user's inhalation; supplying steam to the main air flow passage; retaining liquid in a trap, said trap positioned in said main airflow passage to inhibit flow of liquid along said main airflow passage in an upstream direction from said trap; Including, the vapor delivery device includes an airflow sensor for detecting a user's inhalation on the device; the trap is located in the main airflow passage upstream of the carburetor and downstream of the airflow sensor; The trap is a convoluted portion of the main airflow passageway, the convoluted portion having at least first and second bends, each of the first and second bends bending the convoluted portion through an angle of at least about 90 degrees; the convoluted portion includes a valve arrangement to restrict upstream liquid flow through the convoluted portion relative to downstream liquid flow through the convoluted portion; the valve arrangement comprises a tube, and air flowing in a downstream direction first travels along the inside of the tube and then returns around the outside of the tube; Non-therapeutic methods.

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