WO2022219616A1

WO2022219616A1 - Sorting in the post wick airflow passage

Info

Publication number: WO2022219616A1
Application number: PCT/IB2022/053616
Authority: WO
Inventors: Timothy Wong; Corey Charles Holton IRELAND
Original assignee: 2792684 Ontario Inc.
Priority date: 2021-04-17
Filing date: 2022-04-18
Publication date: 2022-10-20

Abstract

Sorting of droplets within an airflow, based on droplet size, is provided through the use of a set of curves with selected radii of curvature. The momentum of a large droplet will act to resist changing direction quickly as the airflow moves around a corner, which has the effect of pushing large droplets towards the outer edge of an airflow. Smaller droplets are pushed towards the inside angle as the airflow moves around a corner. By connecting curves, and selecting the appropriate radii of curvature, an airflow can be sorted into layers of different droplet sizes.

Description

Sorting in the Post Wick Airflow Passage

Cross Reference to Related Applications

[0001] This application claims the benefit of priority to US Patent Application Serial No. 17/233,471 filed April 17, 2021 and entitled “Sorting in the Post Wick Airflow Passage”, the contents of which are incorporated herein by reference.

Technical Field

[0002] This application relates generally to a system for sorting droplets in an airflow, and more particularly to a system for creating dense layers of droplets within an airflow for use in conjunction with an electronic cigarette or vaporizer.

Background

[0003] Electronic cigarettes and vaporizers are well regarded tools in smoking cessation. In some instances, these devices are also referred to as an electronic nicotine delivery system (ENDS). A nicotine based liquid solution, commonly referred to as e-liquid, often paired with a flavoring, is atomized in the ENDS for inhalation by a user. In some embodiments, e-liquid is stored in a cartridge or pod, which is a removable assembly having a reservoir from which the e-liquid is drawn towards a heating element by capillary action through a wick. In many such ENDS, the pod is removable, disposable, and is s old pre-filled.

[0004] In some ENDS, a refillable tank is provided, and a user can purchase a vaporizable solution with which to fill the tank. This refillable tank is often not removable, and is not intended for replacement. A fillable tank allows the user to control the fill level as desired. Disposable pods are typically designed to carry a fixed amount of vaporizable liquid, and are intended for disposal after consumption of the e-liquid. The ENDS cartridges, unlike the aforementioned tanks, are not typically designed to be refilled. Each cartridge stores a predefined quantity of e-liquid, often in the range of 0.5 to 3ml. In ENDS systems, the e-liquid is typically composed of a combination of any of vegetable glycerine, propylene glycol, nicotine and flavorings. In systems designed for the delivery of other compounds, different compositions may be used. In one such example, a cannabinoid, such as tetrahydrocannabinol (THC) and cannabidiol (CBD), may be carried within an atomizable liquid based on at least one of propylene glycol and vegetable glycerine, and the flavorings may comprise at least one terpene. [0005] In the manufacturing of the disposable cartridge, different techniques are used for different cartridge designs. Typically, the cartridge has a wick that allows e-liquid to be drawn from the e-liquid reservoir to an atomization chamber. In the atomization chamber, a heating element in communication with the wick is heated to encourage aerosolization of the e-liquid. The aerosolized e-liquid can be drawn through a defined air flow passage towards a user’s mouth.

[0006] Figures 1A, IB and 1C provide front, side and bottom views of an exemplary pod 50. Pod 50 is composed of a reservoir 52 having an air flow passage 54, and an end cap assembly 56 that is used to seal an open end of the reservoir 52. End cap assembly has wick feed lines 58 which allow e-liquid stored in reservoir 52 to be provided to a wick (not shown in Figure 1). To ensure that e-liquid stored in reservoir 52 stays in the reservoir and does not seep or leak out, and to ensure that end cap assembly 56 remains in place after assembly, seals 60 can be used to ensure a more secure seating of the end cap assembly 56 in the reservoir 52. In the illustrated embodiment, seals 60 may be implemented through the use of o-rings.

[0007] As noted above, pod 50 includes a wick that is heated to atomize the e-liquid. To provide power to the wick heater, electrical contacts 62 are placed at the bottom of the pod 50. In the illustrated embodiment, the electrical contacts 62 are illustrated as circular. The particular shape of the electrical contacts 62 should be understood to not necessarily germane to the function of the pod 50.

[0008] Because an ENDS device is intended to allow a user to draw or inhale as part of the nicotine delivery path, inlets are provided as part of pre-wick airflow passage 64on the bottom of pod 50. Pre-wick airflow passage 64 allows air to flow through end cap assembly 56 and into an atomization chamber and then through post wick air flow passage 54.

[0009] Shown in cross section in both Figures 1 A and 2B, sitting atop pod 50 is a mouthpiece 68 which can be used as a crude particle size filter by adjusting the placement and sizing of holes that allow the airstream from inside the pod 50 to be delivered to the user. Between the mouthpiece 68 and the top of the reservoir 52 is an absorptive pad 66, often referred to as a spitback pad. Absorptive pad 66 is often made of cotton or another similar material and is designed to absorb droplets. As it sits at the top of a widened chamber, absorptive pad 66 typically encounters large droplets associated with the phenomenon referred to as spitback (which will be discussed below in more detail). As a result, absorptive pad 66 is often able to remove from the airflow entrained droplets associated with a poor user experience. [0010] Figure 2 illustrates a cross section taken along line A in Figure IB. This cross section of the device is shown with a complete (non- sectioned) wick 72and heater 74. End cap assembly 56 resiliently mounts to an end of air flow passage 54 in a manner that allows air inlet 64 to form a complete air path through pod 50. This connection allows airflow from air inlet 64 to connect to the post air flow path through passage 54 through atomization chamber 70. Within atomization chamber 70 is both wick 72 and heater 74. When power is applied to contacts 62, the temperature of the heater increases and allows for the volatilization of e-liquid that is drawn across wick 72.

[0011] Typically the heater 74reaches temperatures well in excess of the vaporization temperature of the e-liquid. This allows for the rapid creation of a vapor bubble next to the heater 74. As power continues to be applied the vapor bubble increases in size, and reduces the thickness of the bubble wall. At the point at which the vapor pressure exceeds the surface tension the bubble will burst and release a mix of the vapor and the e-liquid that formed the wall of the bubble. The e-liquid is released in the form of aerosolized particles and droplets of varying sizes. These particles are drawn into the air flow and into post wick air flow passage 54 and towards the user.

[0012] It should be understood that the airflow passing through post wick air flow passage 54 carries e-liquid vapor and droplets of varying sizes. These droplets are randomly distributed through the airflow. User experience of an ENDS is related to a number of factors including the delivery of nicotine and the flavor compounds in the e-liquid. The size of the droplets entrained by the airflow, after the bubble pops, is associated with a number of different experiences. Flavor compounds are best experienced by smaller particle sizes. Larger particles are less likely to impart flavour, and are associated with other negative experiences including an effect referred to as spitback.

[0013] In one example, in an ENDS device, droplets over 5pm in diameter are typically considered to be the cause of user complaints about spitback.This threshold may vary from device to device. The mitigation of spitback can be achieved through the control of the size of the droplets entrained in the air flow.

[0014] In some conventional ENDS and as shown in Figures 1 A and IB , a mouthpiece that sits atop the pod 50 can be used to modify the path of the airflow exiting air flow passage 54. Because the droplets associated with spitback are larger droplets, they tend to have greater momentum than the droplets associated with flavour and nicotine delivery. By controlling the placement of apertures in the mouthpiece, larger droplets can be kept from ingestion by the user. The laminar air flow in passage 54 will typically direct larger droplets in a straighter air flow. If the mouthpiece has air flow holes placed away from the center of air flow passage 54, larger droplets will typically not be passed through to the user.

[0015] As noted earlier, the atomization process involves heating e-liquid at the surface of the heater until a bubble forms and subsequently ruptures. The vapor from inside the bubble and the droplets of varying sizes are captured by the airflow moving through the atomization chamber. As the airflow proceeds up through the post-wick air flow passage 54, there is no order to the sizing of the droplets, which are distributed in the airflow in what is effectively a random distribution.

[0016] Droplet sorting has been discussed for the purposes of removing large droplets, as in US Patent Application Serial No. 17/146,884 filed January 12, 2021 and entitled “Droplet Size Management through Vortex Generation”. In this application, structures are introduced into the post-wick airflow passage to induce Karman street vortices so that larger droplets are shed and pushed into the walls of the post-wick airflow passage. By removing droplets above a threshold, spitback can be mitigated. Due to the nature of Karman street vortices, although this is effective at the removal of droplets exceeding a size threshold, it is not an effective mechanism for sorting droplets sizes in the airflow.

[0017] The size of droplets in the airflow have been correlated with different aspects of the user experience. As noted earlier, droplets exceeding a size threshold are often associated with spitback. Droplets below this threshold are associated with flavor delivery. It is believed that nicotine delivery is also associated with droplet size. Research has indicated that in some e-liquid compositions, nicotine delivery is associated with droplets below a threshold of approximately lOOOnm. The ability to provide better sorting of droplet sizes could be beneficial to improving the user experience.

[0018] When particles of different sizes are entrained in the same airflow, they can be considered to have effectively the same speed. With the assumption each droplet is effectively the same composition as the other droplets, it should then be understood that each droplet entrained within the airflow has the same density. Assuming that the density of droplets within the airflow is similar, the mass of each droplet is proportional to the size/volume of the droplet. Thus, given a consistent speed and density, the difference in momentum between two droplets within an airflow is proportional to the difference in the mass of the droplets. As such, size, mass and momentum can be treated as proxies for each other, within certain bounds and limits that will be well understood by those skilled in the art. It is recognized that the smallest droplets may be formed as a result of the condensation of vapor and thus may have a different density. Similarly droplets that are far outside the normal distribution of droplet sizes (e.g. more than 2-sigma from the mean in a standard distribution, or an equivalent confidence interval in other distributions, such as a bimodal distribution) may not move at the same speed as others within the same airflow. Nonetheless, it should be understood that for a sufficiently large proportion of the droplets entrained within an airflow, the above congruence is likely to hold.

[0019] For a given airflow, droplets above a certain size can be removed as discussed above, but it should also be understood that it may not be possible or feasible to create more droplets of a given size. Knowing both that droplets of a given size are important to a particular user experience, and that the number of droplets of that size, the question becomes how can the effect of particles of a given size be increased, given the constraint of working with the existing distribution of droplet sizes.

[0020] It would therefore be beneficial to have a mechanism to enhance the effect of droplets of a given size.

Summary

[0021] It is an object of the aspects of the present invention to obviate or mitigate the problems of the above-discussed prior art.

[0022] Sorting of droplets within an airflow to create regions that are substantially exclusively occupied by droplets of a given size will provide layers within the airflow that have higher density of particular droplet sizes. The selection of the radii of curvature for each curve in the post wick airflow path allows for a determination of how droplets will be sorted, with gentle curves typically encouraging less sorting than smaller radii of curvature. By arranging these curves in series, a sorting can be provided that concentrates droplets of different sizes into respectively different layers within the airflow.

[0023] In one aspect of the present invention, there is provided a pod for storing an atomizable liquid, for use in an electronic vaporizer. The pod comprises a post-wick airflow passage for carrying an airflow having entrained droplets of the atomizable liquid, the airflow passage comprises first and second curves. The first curve has a first radius of curvature determined in accordance with characteristics of the atomizable liquid. The second curve is connected in series with the first curve, and has a radius of curvature determined in accordance with characteristics of the atomizable liquid. The output of the second curve is an airflow exhibiting a droplet size sorting.

[0024] In some embodiments, the atomizable liquid is an e-liquid comprising at least one of propylene glycol, vegetable glycerin, nicotine and a flavoring. In some embodiments, the first radius of curvature is different from the second radius of curvature. In other embodiments, the post wick airflow passage is situated between an atomization chamber and a mouthpiece, where optionally, the post-wick airflow passage has sidewalls defined by a reservoir configured to store the atomizable liquid. In some embodiments, the atomization chamber houses a heater for atomizing the atomizable liquid and a wick for drawing the atomizable liquid from the reservoir towards the heater. In further embodiments the post wick airflow passage comprises a third curve connecting the post wick airflow passage to the atomization chamber. In another embodiment, the first and second curve of the post wick airflow passage are positioned away from the atomization chamber and at a mouthpiece end of the post wick airflow passage. In another embodiment, a sidewall of the post-wick airflow passage associated with at least one of the first curve and the second curve is provided by the mouthpiece.

[0025] In another embodiment, the post wick airflow passage is oriented in parallel with a vertical axis of the pod, and wherein an output of the first curve is substantially perpendicular to the vertical axis. In other embodiments, the output of the first curve is connected to an input of the second curve, and where the output of the second curve is substantially parallel to the vertical axis of the pod. In another embodiment, the second curve is directly connected to the first curve.

Brief Description of the Drawings

[0026] Embodiments of the present invention will now be described in further detail by way of example only with reference to the accompanying figure in which:

Figure 1 A is a front view of a prior art pod for use in an ENDS, with a cross sectioned mouthpiece;

Figure IB is a side view of the pod of Figure 1A;

Figure 1C is a bottom view of the pod of Figure 1 A; Figure 2 is a cross section view of the pod of Figures 1A, IB and 1C, shown along section line A-A in Figure IB;

Figure 3 is a sectioned front view of an pod according to an embodiment of the present invention;

Figure 4 is a sectioned side view of the pod of Figure 3 taken along a different axis; Figure 5 A is a sectioned perspective view of the pod of Figure 3; and Figure 5B is a sectioned perspective view of the pod of Figure 3..

[0027] In the above described figures like elements have been described with like numbers where possible.

Detailed Description

[0028] In the instant description, and in the accompanying figures, reference to dimensions may be made. These dimensions are provided for the enablement of a single embodiment and should not be considered to be limiting or essential. Disclosure of numerical range should be understood to not be a reference to an absolute value unless otherwise indicated. Use of the terms about or substantively with regard to a number should be understood to be indicative of an acceptable variation of up to ±10% unless otherwise noted.

[0029] As noted above, there exist methods of crudely sorting particles using vortices. This is referred to in this application as a crude sorting, not because it is ineffective, but because it is directed at a mechanism to remove droplets above a threshold size. Removal of droplets larger than a threshold does increase the relative frequency of droplets below that threshold, but this relative increase is not to be confused with an actual increase. The question, however, should be whether the relative increase in the number of droplets of a given size increases the desired effect of droplets of the given size.

[0030] In considering this question, it is important to consider other somewhat related questions:

• If droplets can be sorted based on their size, without necessarily removing droplets from the airflow, will there be an increase in the user perceived effect of certain droplet sizes?

• If sorting droplets by size enables the creation of layers that are densely populated by a single droplet size, this layer of increased density (without an overall increase in the number of droplets of that size within the airflow), can an increased flavor sensation be provided?

• Can other sensations and effects be provided by sorting droplets into such layers? [0031] Taken together, a question arises as to whether it is possible to increase the user perception of the effect of different droplet sizes. In essence, is it possible to provide a user with the experience associated with vaping a higher level of any component of the e-liquid that is associated with a particular droplet size without increasing the concentration of that component within the e-liquid. It should also be noted that some droplets associated with the carrier fluids (typically propylene glycol and vegetable glycerine) are associated with a user preferred “mouth feel”, and that through the control of density of droplets, associated with one or more of the the carrier fluids, carried within a layer of the airflow can be used to control the delivery of this mouth feel.

[0032] In the following discussion, a solution to this problem is presented making use of droplet sorting. By sorting droplets within an airflow, different droplet sizes can be grouped together within an airflow, effectively concentrating the available droplets of a given size within a portion of the airflow. While increasing the number of droplets of a given size in the airflow as a whole is difficult, increasing the number of droplets of a given size within a portion of the airflow is possible. This can be viewed as creating different regions within the cross section of an airflow that are each quite dense with respect to a particular droplet size. [0033] Experimental testing has been undertaken using airflows that have droplets of given sizes sorted so that they densely occupy a layer within the airflow, and are generally absent from other layers within the airflow. The user experience of such a sorted airflow indicates that users respond to a dense layer of a particular droplet size the same way that they would to an increase in the overall increase in the number of droplets of that particular size.

[0034] Thus, to improve a user experience preferentially associated with a particular droplet size, it is not necessary to increase the number of droplets of that size, but instead creating a dense layer of the particular droplet size within the airflow is sufficient.

[0035] With this understanding that concentrating droplets within an airflow based on the droplet size may be desirable, a mechanism for providing this sorting feature will now be discussed, starting with reference to Figure 3.

[0036] Figure 3 is a cross section view of the pod taken along a cut line parallel to a major axis of the pod 100 Figure 3 illustrates a pod 100 having an airflow feature designed to allow for the sorting of droplets carried in the post wick airflow path. Pod 100 is comprised of a reservoir 102 for storing an atomizable liquid, such as an e-liquid. Within the reservoir is a post-wick airflow path 104. Acting to seal an open end of reservoir 102 is an end cap 106 sized to seal the open end of reservoir 102 which may be accomplished with the use of resilient top cap that may deform when the end cap 106 is inserted into reservoir 102. End cap 106 may not be necessary in all embodiments. In the illustrated embodiment it serves a number of other functions, including providing an atomization chamber in which a wick would be present. As these elements are not necessarily germane to the present invention, elements such as the wick are not illustrated. The role of the wick is to carry e-liquid from the reservoir towards a heater (also not illustrated). The heater heats the e-liquid until it atomizes as discussed above. The airflow proceeds from the bottom of the end cap 106, through the atomization chamber, past the wick and heater, and then through the post wick airflow passage 104. Within post wick airflow passage 104 the airflow may be effectively laminar. It should be noted that in contrast to the illustrated prior art pods, post-wick airflow passage 104 is not located in a central location within the pod 100. Instead, post wick airflow passage 104 is situated along an outer wall of the reservoir 102.

[0037] Atop reservoir 102 is a mouthpiece 108 which provides the physical interface through which the user draws on the device and through which the user is provided the e-liquid laden airflow. Mouthpiece 108 includes an aperture 110, here illustrated as separate openings 110a and 110b. Aperture 110 allows for the post wick airflow passage 104 to have fluid communication with the user.

[0038] Where the prior art made use of a straight post- wick airflow passage, and provided rudimentary droplet filtering through the off center placement of apertures, droplet sorting is performed through the design of the post wick airflow passage 104. As the airflow within post wick airflow passage 104 proceeds towards the mouthpiece 108, airflow passage 104 provides a set of connected curves 112a and 112b. As an airflow passes through one of the curves, droplets with higher momentum (which were previously established to be larger droplets) will be less likely to follow the curve. This inertia will have the effect of pushing larger droplets towards the outside of the curve. A number of other phenomena, will act upon the smaller droplets, including low pressure zones around curves and spin associated with smaller droplets. This will result in a migration of smaller droplets towards the interior side of a curve. As the airflow passes through the second curve, droplets within the airflow are again required to leave their current trajectory, which will be resisted by the inertia of the larger droplets. As such, the larger droplets will again be pushed towards the outer edge of the airflow as it goes around the curve. Similarly, smaller droplets will be pushed towards the inner edge of the airflow as it goes around the curve. While illustrated in this cross section as two pairs of curves, 112a on the right and 112a on the left followed by 112b on the right and 112b on the left, it should be understood, that instead of simply forming an s-shape curve, this is followed not just in this currently illustrated plane, but also in an orthogonal plane, which will be illustrated in a subsequent figure. This results in a post-wick airflow passage that provides, at its top, a three-dimensional structure that is the shape caused by the rotation of an S-curve. The first and second curves can be differently sized, that is they can have different radii of curvature, and different lengths. By tuning these parameters, the effect on the larger and smaller droplets can be accentuated or attenuated, so that larger droplets can be pushed to the outside of the airflow, with smaller droplets pushed towards the interior of the airflow. This can result in a roughly cylindrical airflow with large droplets concentrated on the outside of the airflow, and smaller droplets concentrated in the middle of the airflow. Different tuning of the radii of curvature can provide differing degrees of concentration. [0039] Figure 4 illustrates a cross section of pod 100 along the minor axis perpendicular to the cut line used in Figure 3. The atomization chamber 114 shown below the post-wick airflow passage 104 would typically house a wick (not shown), and is defined by structures within end cap 106. When a user draws on pod 100, air enters the bottom of the pod 100 through inlets within end cap 106, and then proceeds to atomization chamber 114. Within atomization chamber 114, e-liquid is heated and atomized, with the resulting vapor and droplets being entrained within the airflow. The airflow passes into post wick airflow passage 104, and proceeds towards the mouthpiece 108. Curve 112c shows the airflow path bend in a direction different than is shown in Figure 3. If, in Figure 3, bends 112a are curves along the X-axis, then the illustrated curve 112c would be a curve along a Y-axis, with curves 112b and 112d being curves in a Z-axis. In effect, after a long vertical straight away section in post-wick airflow passage 104, the airflow passage 104 has curves 112a and 112c towards both horizontal axes, which are followed by curves 112b and 112c again towards the vertical axis. As can be seen, in the illustrated embodiment, in the area around curves 112c and 112d, part of the post wick airflow passage 104 is formed by the mouthpiece 108. It should be understood that in other embodiments, all of the sidewalls of the airflow passage 104 may be formed by the reservoir 102, while in others, all of the sidewalls could be formed in the mouthpiece 108.

[0040] As noted above, when passing through a curve, the differential momentum associated with the differently sized droplets will force larger droplets towards the outside of the airflow as it bends around the curve and other factors can be relied upon to concentrate smaller droplets towards the inside of the curve. By connecting curves, this can be repeated, and the sorting effect is magnified. It should be understood that the curves can be directly connected to each other, or they can be connected by another straight away section. The radius of curvature of curves 112a, 112b, 112c and 112d is important, as it defines how the sorting will occur. As noted above, in some embodiments the radii of curvature of the first and second curves will be different from each other. This will be discussed in greater detail below.

[0041] It should be noted that connecting atomization chamber 114 to post- wick airflow passage 104 is another curve 116, and the airflow will also experience a curve within the atomization chamber. Taken together, this forms another S-curve. This S-curve may assist in droplet size sorting, but it should be understood that its effect is not likely to be prominent as there are series of structures, such as the wick, that will interact with the airflow. Curve 116 may also be understood as required to connect a post-wick airflow passage 104 that is situated along a sidewall of a reservoir, to an atomization chamber 114 that is positioned away from the edge of pod 100.

[0042] Figures 5A and 5B illustrate cross sections of pod 100 presented in perspective. Pod 100 has a reservoir 102 whose walls also define post-wick airflow passage 104. The open end (bottom) of reservoir 102 is designed to mate with end cap 106 so that it can be sealed to prevent egress of e-liquid stored in the reservoir 102. A mouthpiece 108 having an aperture 110 sits atop reservoir 102, and in the current embodiment, the interface between the mouthpiece 108 and the reservoir 102 helps define curves 112a, 112b, 112c and 112d in the post wick airflow passage 104. Within end cap 106 is atomization chamber 114 which houses a wick and a heater (not shown) that are used to atomize the e-liquid drawn by the wick from the reservoir 102 into the atomization chamber. Due to the optional placement of the atomization chamber, an airflow passage 116 is also defined, which as noted above may contribute to droplet size sorting.

[0043] As an airflow passes through the atomization chamber 114 it will entrain droplets of varying sizes as well as e-liquid vapor. This airflow will proceed into post-wick airflow passage 104, and the distribution of the droplets according to their size can be considered to be effectively random. The droplets entrained within the airflow have a momentum associated with the speed with which they are moving and their mass. The increased momentum will provide the droplet with an inertia so that it will resist changing its direction of motion. Larger droplets will tend to resist the change in motion more than smaller droplets. As a result, smaller droplets will more easily move through a curve, such as any one of 112a, 112b, 112c and 112d. The larger droplets will take a wider path through these curves, and will thus be sorted towards the outside of the airflow. As such, the curves within the post-wick airflow path can be used to create a sorted airflow. The sorted airflow will have layers with different droplet sizes in each layer (although it should be understood that the distribution of the droplets may result in the boundaries between two layers being indistinct.) [0044] Each of curves 112a-112d have a radius of curvature. The radius of curvature can also be understood as a parameter that defines how “tight” a corner defined by the curve is. A larger radius of curvature is associated with a more gentle curve. A small radius of curvature is associated with a more abrupt change in direction. The radius of curvature of each of the curves 112a-112d are defined by the desired sorting function. The lower bound on the radius of curvature is defined by the properties of the e-liquid in question. The density of the e-liquid will be associated with the mass of droplets of any given size. If flavour droplets are determined to be droplets of up to 5 pm, then the radius of curvature should not be so small that the curve does not provide droplets of 5pm sufficient space to navigate the curve. Each radius of curvature provides an opportunity not only to sort droplets based on size, but also to filter out droplets above a threshold size, as droplets above the threshold will have too much inertia and will not be able to clear the curve before colliding with the wall. The upper limit on the radius of curvature will be defined in part by the size of the pod, and by the properties of the e-liquid. If a curve is too gentle, it will be navigable by all droplets. The result will be that there is insufficient sorting, or that more curves will be required to provide the required degree of droplet sorting. In one embodiment, the first curve, whether it is 112a or 112c, has a first radius of curvature, while the second curve, whether it is 112b or 112d, has a second radius of curvature. The first and second radii of curvature are different. This allows for an airflow with an unsorted distribution of differently sized droplets to be turned into an airflow sorted by droplet size. In some embodiments, the selection of differing radii of curvature allows for an airflow in which smaller droplets are pushed to the inside of the airflow, and larger droplets are pushed to the outside of the airflow.

[0045] In the embodiment illustrated in Figures 5A and 5B, curves 112a and 112c are the first curves and they have a radius of curvature of approximately 1.5mm. The second curve is illustrated as curves 112b and 112d, and has a radius of curvature of 4mm. It should be noted that in other embodiments these dimensions may vary. This variance may result in the ratio between the radii being constant, while in other embodiments the resulting ratio may be different. Changing the characteristics of the curve can be done taking into account the characteristics of the e-liquid among other factors.

[0046] The use of curves in pairs allows for curves in different orientations to be used in conjunction with each other to allow for the change in direction to be offset, allowing the output of the final curve to be directed out of the mouthpiece of the pod. In the illustrated embodiment this allows for the output of the second curve to exit the top of the pod. In some embodiments, an odd number of curves can be used. These curves can be connected to allow for the output of the final curve to exit at a selected location of the pod. It should be noted that by connecting a series of curves, either of the same or different radii of curvature, a spiral or corkscrew shaped structure could be created.

[0047] Although presented below in the context of use in an electronic nicotine delivery system such as an electronic cigarette (e-cig) or a vaporizer (vape) it should be understood that the scope of protection need not be limited to this space, and instead is delimited by the scope of the claims. Embodiments of the present invention are anticipated to be applicable in areas other than ENDS, including (but not limited to) other vaporizing applications.

[0048] In the instant description, and in the accompanying figures, reference to dimensions may be made. These dimensions are provided for the enablement of a single embodiment and should not be considered to be limiting or essential. The sizes and dimensions provided in the drawings are provided for exemplary purposes and should not be considered limiting of the scope of the invention, which is defined solely in the claims.

Claims

1. A pod for storing an atomizable liquid, for use in an electronic vaporizer, the pod comprising: a post-wick airflow passage for carrying an airflow having entrained droplets of the atomizable liquid, the airflow passage comprising: a first curve having a first radius of curvature determined in accordance with characteristics of the atomizable liquid ; and a second curve, connected in series with the first curve, having a second radius of curvature determined in accordance with characteristics of the atomizable liquid, and having an output airflow sorted by droplet size.

2. The pod of claim 1 wherein the atomizable liquid is an e-liquid comprising at least one of propylene glycol, vegetable glycerin, nicotine and a flavoring.

3. The pod of claim 1 wherein the atomizable liquid comprises at least one of a cannabinoid, propylene glycol, vegetable glycerin and a terpene.

4. The pod of claim 1 wherein the first radius of curvature is different than the second radius of curvature.

5. The pod of claim 1 wherein the post wick airflow passage is situated between an atomization chamber and a mouthpiece.

5. The pod of claim 5 wherein the post- wick airflow passage has sidewalls defined by a reservoir configured to store the atomizable liquid.

7. The pod of claim 6 wherein the atomization chamber houses a heater for atomizing the atomizable liquid and a wick for drawing the atomizable liquid from the reservoir towards the heater.

8. The pod of claim 5 wherein the post wick airflow passage comprises a third curve connecting the post wick airflow passage to the atomization chamber.

9. The pod of claim 5 wherein the first and second curve of the post wick airflow passage are positioned away from the atomization chamber and at a mouthpiece end of the post wick airflow passage.

10. The pod of claim 5 wherein a sidewall of the post-wick airflow passage associated with at least one of the first curve and the second curve is provided by the mouthpiece.

11. The pod of claim 1 wherein the post wick airflow passage is oriented in parallel with a vertical axis of the pod, and wherein an output of the first curve is substantially perpendicular to the vertical axis.

12. The pod of claim 1 wherein the output of the first curve is connected to an input of the second curve, and where the output of the second curve is substantially parallel to the vertical axis of the pod.

13. The pod of claim 1 wherein the second curve is directly connected to the first curve.

14. The pod of claim 1 wherein the first curve and the second curve bend in different directions.

15. The pod of claim 1 wherein the first radius of curvature is 1.5mm.

16. The pod of claim 1 wherein the second radius of curvature is 4mm.