WO2019211337A1

WO2019211337A1 - A consumable for a smoking substitute device

Info

Publication number: WO2019211337A1
Application number: PCT/EP2019/061157
Authority: WO
Inventors: Pete LOMAS; Chris Lord
Original assignee: Nerudia Limited
Priority date: 2018-05-01
Filing date: 2019-05-01
Publication date: 2019-11-07
Also published as: GB201807157D0; EP3787426A1

Abstract

A consumable for a smoking substitute device, and a smoking substitute device including the consumable. The consumable comprising: a tank, for storing vapourisable liquid; a heater assembly; and a mouthpiece, fluidly connected to the tank via an outlet. The outlet is provided as an elongate tube, connecting the tank to the mouthpiece, and wherein a portion of the outlet proximal to the heater assembly has a cross-sectional area of more than 5 mm2.

Description

A CONSUMABLE FOR A SMOKING SUBSTITUTE DEVICE

This application claims priority to GB 1807157.1 filed 1 May 2018, the contents and elements of which are herein incorporated by reference for all purposes.

Field of the Invention

[0001] The present invention relates to smoking substitute devices, and particularly, although not exclusively, to providing a consumable for a smoking substitute device including a chimney configured to limit the likelihood of drawing droplets of liquid into an outlet.

Background

[0002] The smoking of tobacco is generally considered to expose a smoker to potentially harmful substances. It is generally thought that a significant amount of the potentially harmful substances are generated through the heat caused by the burning and/or combustion of the tobacco and the constituents of the burnt tobacco in the tobacco smoke itself.

[0003] Combustion of organic material such as tobacco is known to produce tar and other potentially harmful by-products. There have been proposed various smoking substitute devices in order to avoid the smoking of tobacco.

[0004] Such smoking substitute devices can form part of nicotine replacement therapies aimed at people who wish to stop smoking and overcome a dependence on nicotine.

[0005] Smoking substitute devices, which may also be known as electronic nicotine delivery systems, may comprise electronic systems that permit a user to simulate the act of smoking by producing an aerosol, also referred to as a“vapour”, which is drawn into the lungs through the mouth (inhaled) and then exhaled. The inhaled aerosol typically bears nicotine and/or flavourings without, or with fewer of, the odour and health risks associated with traditional smoking.

[0006] In general, smoking substitute devices are intended to provide a substitute for the rituals of smoking, whilst providing the user with a similar experience and satisfaction to those experienced with traditional smoking and tobacco products.

[0007] The popularity and use of smoking substitute devices has grown rapidly in the past few years. Although originally marketed as an aid to assist habitual smokers wishing to quit tobacco smoking, consumers are increasingly viewing smoking substitute devices as desirable lifestyle accessories. Some smoking substitute devices are designed to resemble a traditional cigarette and are cylindrical in form with a mouthpiece at one end. Other smoking substitute devices do not generally resemble a cigarette (for example, the smoking substitute device may have a generally box-like form).

[0008] There are a number of different categories of smoking substitute devices, each utilising a different smoking substitute approach. A smoking substitute approach

corresponds to the manner in which the substitute system operates for a user.

[0009] One approach for a smoking substitute device is the so-called“vaping” approach, in which a vapourisable liquid, typically referred to (and referred to herein) as“e-liquid”, is heated by a heating device to produce an aerosol vapour which is inhaled by a user. An e- liquid typically includes a base liquid as well as nicotine and/or flavourings. The resulting vapour therefore typically contains nicotine and/or flavourings. The base liquid may include propylene glycol and/or vegetable glycerin.

[0010] A typical vaping smoking substitute device includes a mouthpiece, a power source (typically a battery), a tank for containing e-liquid, as well as a heating device. In use, electrical energy is supplied from the power source to the heating device, which heats the e- liquid to produce an aerosol (or“vapour”) which is inhaled by a user through the mouthpiece.

[0011] Vaping smoking substitute devices can be configured in a variety of ways. For example, there are“closed system” vaping smoking substitute devices which typically have a sealed tank and heating element which is pre-filled with e-liquid and is not intended to be refilled by an end user. One subset of closed system vaping smoking substitute devices include a main body which includes the power source, wherein the main body is configured to be physically and electrically coupled to a consumable including the tank and the heating element. In this way, when the tank of a consumable has been emptied, the main body can be reused by connecting it to a new consumable. Another subset of closed system vaping smoking substitute devices are completely disposable, and intended for one-use only.

[0012] There are also“open system” vaping smoking substitute devices which typically have a tank that is configured to be refilled by a user, so the device can be used multiple times.

[0013] An example vaping smoking substitute device is the myblu™ e-cigarette. The myblu™ e-cigarette is a closed system device which includes a main body and a

consumable. The main body and consumable are physically and electrically coupled together by pushing the consumable into the main body. The main body includes a rechargeable battery. The consumable includes a mouthpiece, a sealed tank which contains e-liquid, as well as a heating device, which for this device is a heating filament coiled around a portion of a wick which is partially immersed in the e-liquid. The device is activated when a microprocessor on board the main body detects a user inhaling through the mouthpiece. When the device is activated, electrical energy is supplied from the power source to the heating device, which heats e-liquid from the tank to produce a vapour which is inhaled by a user through the mouthpiece.

[0014] Another example vaping smoking substitute device is the blu PRO™ e-cigarette. The blu PRO™ e-cigarette is an open system device which includes a main body, a (refillable) tank, and a mouthpiece. The main body and tank are physically and electrically coupled together by screwing one to the other. The mouthpiece and refillable tank are physically coupled together by screwing one into the other, and detaching the mouthpiece from the refillable tank allows the tank to be refilled with e-liquid. The device is activated by a button on the main body. When the device is activated, electrical energy is supplied from the power source to a heating device, which heats e-liquid from the tank to produce a vapour which is inhaled by a user through the mouthpiece.

[0015] Another approach for a smoking substitute device is the so-called "heat not burn" (“HNB”) approach in which tobacco (rather than e-liquid) is heated or warmed to release vapour. The tobacco may be leaf tobacco or reconstituted tobacco. The vapour may contain nicotine and/or flavourings. In the HNB approach the intention is that the tobacco is heated but not burned, i.e. does not undergo combustion.

[0016] A typical HNB smoking substitute device may include a main body and a

consumable. The consumable may include the tobacco material. The main body and consumable may be configured to be physically coupled together. In use, heat may be imparted to the tobacco material by a heating device that is typically located in the main body, wherein airflow through the tobacco material causes moisture in the tobacco material to be released as vapour. A vapour may be formed from a carrier in the tobacco material (this carrier may for example include propylene glycol and/or vegetable glycerin) and additionally volatile compounds released from the tobacco. The released vapour may be entrained in the airflow drawn through the tobacco.

[0017] As the vapour passes through the smoking substitute device (entrained in the airflow) from an inlet to a mouthpiece (outlet), the vapour cools and condenses to form an aerosol (also referred to as a vapour) for inhalation by the user. The aerosol will normally contain the volatile compounds.

[0018] In HNB smoking substitute devices, heating as opposed to burning the tobacco material is believed to cause fewer, or smaller quantities, of the more harmful compounds ordinarily produced during smoking. Consequently, the HNB approach may reduce the odour and/or health risks that can arise through the burning, combustion and pyrolytic degradation of tobacco.

[0019] An example of the HNB approach is the IQOS® smoking substitute device from Philip Morris Ltd. The IQOS® smoking substitute device uses a consumable, including reconstituted tobacco located in a wrapper. The consumable includes a holder incorporating a mouthpiece. The consumable may be inserted into a main body that includes a heating device. The heating device has a thermally conductive heating knife which penetrates the reconstituted tobacco of the consumable, when the consumable is inserted into the heating device. Activation of the heating device heats the heating element (in this case a heating knife), which, in turn, heats the tobacco in the consumable. The heating of the tobacco causes it to release nicotine vapour and flavourings which may be drawn through the mouthpiece by the user through inhalation.

[0020] A second example of the HNB approach is the device known as "Glo"® from British American Tobacco p.l.c. Glo® comprises a relatively thin consumable. The consumable includes leaf tobacco which is heated by a heating device located in a main body. When the consumable is placed in the main body, the tobacco is surrounded by a heating element of the heating device. Activation of the heating device heats the heating element, which, in turn, heats the tobacco in the consumable. The heating of the tobacco causes it to release nicotine vapour and flavourings which may be drawn through the consumable by the user through inhalation. The tobacco, when heated by the heating device, is configured to produce vapour when heated rather than when burned (as in a smoking apparatus, e.g. a cigarette). The tobacco may contain high levels of aerosol formers (carrier), such as vegetable glycerine (“VG”) or propylene glycol (“PG”).

[0021] The present inventor(s) have observed that in previous devices, droplets of unvapourised liquid are drawn into a mouthpiece of the consumable and may be inhaled by a user of the device.

[0022] The present invention has been devised in light of the above considerations.

Summary

[0023] At its broadest, aspects of the invention are concerned with providing an outlet connected between a heater assembly and a mouthpiece which is configured to reduce the air velocity of air drawn therethrough.

[0024] In a first aspect, the invention provides a consumable for a smoking substitute device, the consumable comprising: a tank, for storing vapourisable liquid; a heater assembly; and a mouthpiece, fluidly connected to the tank via an outlet; wherein the outlet is provided as an elongate tube, connecting the tank to the mouthpiece, and wherein a portion of the outlet proximal to the heater assembly has a cross-sectional area of more than 5mm².

[0025] Advantageously, an outlet with such a cross-sectional area has a reduced airflow velocity for a given pressure, and therefore the likelihood of unvapourised droplets of vapourisable liquid being drawn into the mouthpiece is diminished. [0026] The outlet may extend from at point at or proximal to a first end of the consumable, where it fluidly connects to the tank, to a point at or proximal to a second end of the consumable, where it fluidly connects to the mouthpiece. The heater assembly may be a coil and wick assembly, which is fluidly connected to the tank. The outlet may be fluidly connected to the tank via the heater assembly. The outlet may extend along a length which is substantially contained within the tank.

[0027] In a second aspect, the invention provides a smoking substitute device including the consumable as set out with respect to the first aspect.

[0028] Optional features of the invention will now be set out. These are applicable singly or in any combination with any aspect of the invention.

[0029] The outlet may have a cross-sectional area of no more than 10 mm².

[0030] The outlet may have an internal diameter of more than 2.5 mm. This internal diameter may be measured across the portion having a cross-sectional area of more than 5mm².

[0031] The internal diameter of the outlet may be no more than 4 mm.

[0032] The cross-sectional area out of the outlet may be substantially constant along its length. The internal diameter may be substantially constant along its length. By along its length, it may be meant that the cross-sectional area or internal diameter may take a first value at a point proximal to the heater, and have the same value at a point distal to the heater, without varying in a direction joining these two points.

[0033] An internal diameter of the outlet may be at least 20% of a width of the tank. The tank may have a width, as measured in the same direction as the internal diameter of the outlet, is at least 10 mm and no more than 20 mm.

[0034] The outlet may be fluidly connected at a first end to the heater assembly and fluidly connected at a second end to the mouthpiece, and the cross-sectional area at the first end may be more than 5 mm².

[0035] The consumable may further comprise a filter, disposed between the tank and an outlet of the mouthpiece, which is configured to be impermeable to unvapourised liquid and permeable to vapourised liquid. The filter may be positioned in or adjacent to the

mouthpiece.

[0036] The consumable may include an air inlet, disposed at an opposite end of the consumable to the mouthpiece, and the air inlet, heater assembly, and mouthpiece define a path for airflow through the consumable in that order. The filter may be disposed between the heater assembly and the mouthpiece. [0037] The filter may be formed from a fabric, so as to be permeable to vapourised liquid but impermeable to unvapourised liquid. The filter may be formed from a mesh so as to be permeable to vapourised liquid but impermeable to unvapourised liquid. The filter may be a gas-permeable and liquid-impermeable membrane.

Brief Description of the Drawings

[0038] Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which:

[0039] Figure 1(a) shows an example smoking substitute device;

[0040] Figure 1(b) shows the main body of the smoking substitute device of Figure 1 (a) without the consumable;

[0041] Figure 1(c) shows the consumable of the smoking substitute device of Figure 1(a) without the main body;

[0042] Figure 2(a) is a schematic view of the main body of the smoking substitute device of Figure 1(a);

[0043] Figure 2(b) is a schematic view of the consumable of the smoking substitute device of Figure 1 (b);

[0044] Figure 3 is a cross-sectional view of a consumable for the smoking substitute device. Detailed Description and Further Optional Features

[0045] Aspects and embodiments of the present invention will now be discussed with reference to the accompanying figures. Further aspects and embodiments will be apparent to those skilled in the art. All documents mentioned in this text are incorporated herein by reference

[0046] Figure 1(a) shows an example smoking substitute device 1 10. In this example, the smoking substitute device 110 includes a main body 120 and a consumable 150. The consumable 150 may alternatively be referred to as a“pod”.

[0047] In this example, the smoking substitute device 1 10 is a closed system vaping device, wherein the consumable 150 includes a sealed tank 156 and is intended for one-use only.

[0048] Figure 1(a) shows the smoking substitute device 110 with the main body 120 physically coupled to the consumable 150.

[0049] Figure 1 (b) shows the main body 120 of the smoking substitute device 110 without the consumable 150. [0050] Figure 1(c) shows the consumable 150 of the smoking substitute device 110 without the main body 120.

[0051] The main body 120 and the consumable 150 are configured to be physically coupled together, in this example by pushing the consumable 150 into an aperture in a top end 122 of the main body 120. In other examples, the main body 120 and the consumable could be physically coupled together by screwing one onto the other, or through a bayonet fitting, for example. An optional light 126, e.g. an LED located behind a small translucent cover, is located a bottom end 124 of the main body 120. The light 126 may be configured to illuminate when the smoking substitute device 110 is activated.

[0052] The consumable 150 includes a mouthpiece (not shown) at a top end 152 of the consumable 150, as well as one or more air inlets (not shown in Fig. 2) so that air can be drawn into the smoking substitute device 110 when a user inhales through the mouthpiece. At a bottom end 154 of the consumable 150, there is located a tank 156 that contains e- liquid. The tank 156 may be a translucent body, for example.

[0053] The tank 156 preferably includes a window 158, so that the amount of e-liquid in the tank 156 can be visually assessed. The main body 120 includes a slot 128 so that the window 158 of the consumable 150 can be seen whilst the rest of the tank 156 is obscured from view when the consumable 150 is inserted into the aperture in the top end 122 of the main body 120.

[0054] The tank 156 may be referred to as a“clearomizer” if it includes a window 158, or a “cartomizer” if it does not.

[0055] The consumable 150 may identify itself to the main body 120, via an electrical interface, RFID chip, or barcode.

[0056] Figure 2(a) is a schematic view of the main body 120 of the smoking substitute device 1 10.

[0057] Figure 2(b) is a schematic view of the consumable 150 of the smoking substitute device 1 10.

[0058] As shown in Figure 2(a), the main body 120 includes a power source 140, a control unit 130, a memory 132, a wireless interface 134, an electrical interface 136, and, optionally, one or more additional components 138.

[0059] The power source 140 is preferably a battery, more preferably a rechargeable battery.

[0060] The control unit 130 may include a microprocessor, for example. [0061] The memory 132 is preferably includes non-volatile memory. The memory may include instructions which, when implemented, cause the control unit 130 to perform certain tasks or steps of a method.

[0062] The wireless interface 134 is preferably configured to communicate wirelessly with the mobile device 2, e.g. via Bluetooth®. To this end, the wireless interface 134 could include a Bluetooth® antenna. Other wireless communication interfaces, e.g. WiFi®, are also possible. As discussed above, the wireless interface 134 may be configured to communicate wirelessly with the remote server 2.

[0063] The electrical interface 136 of the main body 120 may include one or more electrical contacts. The electrical interface 136 may be located in, and preferably at the bottom of, the aperture in the top end 122 of the main body 120. When the main body 120 is physically coupled to the consumable 150, the electrical interface 136 may be configured to pass electrical power from the power source 140 to (e.g. a heating device of) the consumable 150 when the smoking substitute device 1 10 is activated, e.g. via the electrical interface 160 of the consumable 150 (discussed below). When the main body 120 is not physically coupled to the consumable 150, the electrical interface may be configured to receive power from the charging station 6. The electrical interface 136 may also be used to identify the consumable 150 from a list of known consumables. For example, the consumable may be a particular flavour and/or have a certain concentration of nicotine. This can be identified to the control unit 130 of the main body 120 when the consumable is connected to the main body.

Additionally, or alternatively, there may be a separate communication interface provided in the main body 120 and a corresponding communication interface in the consumable 150 such that, when connected, the consumable can identify itself to the main body 120.

[0064] The additional components 138 of the main body 120 may include the optional light 126 discussed above.

[0065] The additional components 138 of the main body 120 may, if the power source 140 is a rechargeable battery, include a charging port configured to receive power from the charging station 6. This may be located at the bottom end 124 of the main body 120.

Alternatively, the electrical interface 136 discussed above is configured to act as a charging port configured to receive power from the charging station 6 such that a separate charging port is not required.

[0066] The additional components 138 of the main body 120 may, if the power source 140 is a rechargeable battery, include a battery charging control circuit, for controlling the charging of the rechargeable battery. However, a battery charging control circuit could equally be located in the charging station 6 (if present). [0067] The additional components 138 of the main body 120 may include an airflow sensor for detecting airflow in the smoking substitute device 1 10, e.g. caused by a user inhaling through a mouthpiece 166 (discussed below) of the smoking substitute device 1 10. The smoking substitute device 110 may be configured to be activated when airflow is detected by the airflow sensor. This optional sensor could alternatively be included in the consumable 150 (though this is less preferred where the consumable 150 is intended to be disposed of after use, as in this example). The airflow sensor can be used to determine, for example, how heavily a user draws on the mouthpiece or how many times a user draws on the mouthpiece in a particular time period.

[0068] The additional components 138 of the main body 120 may include an actuator, e.g. a button. The smoking substitute device 110 may be configured to be activated when the actuator is actuated. This provides an alternative to the airflow sensor noted, as a mechanism for activating the smoking substitute device 1 10.

[0069] As shown in Figure 2(b), the consumable 150 includes the tank 156, an electrical interface 160, a heating device 162, one or more air inlets 164, a mouthpiece 166, and, optionally, one or more additional components 168.

[0070] The electrical interface 160 of the consumable 150 may include one or more electrical contacts. The electrical interface 136 of the main body 120 and an electrical interface 160 of the consumable 150 are preferably configured to contact each other and therefore electrically couple the main body 120 to the consumable 150 when the main body 120 is physically coupled to the consumable 150. In this way, electrical energy (e.g. in the form of an electrical current) is able to be supplied from the power source 140 in the main body 120 to the heating device 162 in the consumable 150.

[0071] The heating device 162 is preferably configured to heat e-liquid contained in the tank 156, e.g. using electrical energy supplied from the power source 140. In one example, the heating device 162 may include a heating filament and a wick, wherein a first portion of the wick extends into the tank 156 in order to draw e-liquid out from the tank 156, and wherein the heating filament coils around a second portion of the wick located outside the tank 156.

In this example, the heating filament is configured to heat up e-liquid drawn out of the tank 156 by the wick to produce an aerosol vapour.

[0072] The one or more air inlets 164 are preferably configured to allow air to be drawn into the smoking substitute device 110, when a user inhales through the mouthpiece 166.

[0073] In use, a user activates the smoking substitute device 110, e.g. through actuating an actuator included in the main body 120 or by inhaling through the mouthpiece 166 as described above. Upon activation, the control unit 130 may supply electrical energy from the power source 140 to the heating device 162 (via electrical interfaces 136, 166), which may cause the heating device 162 to heat e-iiquid drawn from the tank 156 to produce a vapour which is inhaled by a user through the mouthpiece 166.

[0074] As an example of one of the one or more additional components 168, an interface for obtaining an identifier of the consumable may be provided. As discussed above, this interface may be, for example, an RFID reader, a barcode or QR code reader, or an electronic interface which is able to identify the consumable to the main body. The consumable may, therefore include any one or more of an RFID chip, a barcode or QR code, or memory within which is an identifier and which can be interrogated via the electronic interface in the main body.

[0075] Of course, a skilled reader would readily appreciate that the smoking substitute device 110 shown in Figs. 2 and 3 shows just one example implementation of a smoking substitute device, and that other forms of smoking substitute device could be used.

[0076] By way of example, a HNB smoking substitute device including a main body and a consumable could be used, instead of the smoking substitute device 110. One such HNB smoking substitute device is the IQOS® smoking substitute device discussed above.

[0077] As another example, an open system vaping device which includes a main body, a refillable tank, and a mouthpiece could be used, instead of the smoking substitute device 110. One such open system vaping device is the blu PRO™ e-cigarette discussed above.

[0078] As another example, an entirely disposable (one use) smoking substitute device could be used as the smoking substitute device.

[0079] Figure 3 shows a cross-sectional view of a consumable 150 as discussed previously. Broadly, the consumable is formed of a tank 156, a heater assembly 162, an outlet 306, and a mouthpiece 166. The consumable includes an air inlet 164, which allows air to flow into the heater assembly, through the outlet, to the mouthpiece 166.

[0080] In this example, the heater assembly is a coil and wick assembly. As such, a coil is present within the heater assembly with a wick passing therethrough. The wick is then exposed to a liquid filled volume of the tank 156, so that vapourisable liquid contained therein is wicked into an interior of the heater assembly. Thus, in use, the coil is heated via an electrical current and vapourisable liquid within the wick is vapourised. This heating is generally triggered by the user drawing from the mouthpiece, causing an airflow past the coil.

[0081] The outlet 306 in this example, which may be referred to a chimney or airway tube has an internal diameter, ID, of around 3.5 mm. This gives a cross-sectional area of around 9.6 mm². Such a cross-sectional area has been found to limit the air velocity for any given flow rate, such that it is less likely that droplets of unvapoursed liquid will be drawn into the outlet and through to the mouthpiece 166.

[0082] As can be seen in this example, the cross-sectional area of the outlet is substantially constant along most or all of its length. There is a slight increase in the cross-sectional area towards an upper end of the outlet, near to the mouthpiece 166. However the cross-sectional area at this point in the outlet has a limited impact on the air velocity within the heater assembly 304.

[0083] Located, in this example within the mouthpiece 166, is a filter 302. The filter in this example is a fabric which is permeable to gas or vapourised liquid whilst impermeable to liquid or unvapourised liquid. The filter covers the mouthpiece outlets 314a and 314b, so that liquid or unvapourised liquid cannot pass therethrough. The filter is generally tubular, so that it sits snugly within the mouthpiece 166. Whilst the filter in this example is within the mouthpiece, it will be appreciated that it could, instead, be located within the outlet 306 or at any position between the heater assembly 162 and the mouthpiece outlets 314a 314b. The filter in this example is made from cotton or another fibre.

[0084] The mouthpiece in this example is a plastic moulding providing an outer casing and two apertures 170a, 170b for corresponding clips 308a, 308b of the tank 156. The

mouthpiece outlets 314a and 314b are provided as apertures through the plastic moulding. The clips of the tank engage the corresponding apertures so to retain the mouthpiece adjacent to the tank. The interior of the mouthpiece 166 between the apertures 310a and 310b and mouthpiece outlets 314a 314b is generally defined as a mouthpiece chamber 312.

[0085] While the invention has been described in conjunction with the exemplary

embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. Accordingly, the exemplary embodiments of the invention set forth above are considered to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from the spirit and scope of the invention. List of Features

110 Smoking substitute device 120 Main body

122 Top end of main body 124 Bottom end of main body 126 Light

128 Slot

130 Control unit

132 Memory

134 Wireless interface

136 Electrical interface 138 Additional component 140 Power source

150 Consumable

152 Top end of consumable 154 Bottom end of consumable 156 Tank

158 Window

160 Electrical interface 162 Heating device

164 Air inlets

166 Mouthpiece

168 Additional components 170a, b Aperture for clip

302 Filter

304 Tank housing

306 Chimney

308a, b Clip

312 Mouthpiece chamber

314a,b Mouthpiece outlets

Claims

1. A consumable (150) for a smoking substitute device (110), the consumable comprising:

a tank (156), for storing vapourisable liquid;

a heater assembly (162); and

a mouthpiece (166), fluidly connected to the tank via an outlet (306);

wherein the outlet is provided as an elongate tube, connecting the tank to the mouthpiece, and wherein a portion of the outlet proximal to the heater assembly has a cross- sectional area of more than 5 mm².

2. The consumable of claim 1 , wherein the outlet has a cross-sectional area of no more than 10 mm².

3. The consumable of either claim 1 or claim 2, wherein the outlet has an internal diameter of more than 2.5 mm.

4. The consumable of claim 3, wherein the internal diameter of the outlet is no more than 4 mm.

5. The consumable of any preceding claim, wherein the cross-sectional area of the outlet is substantially constant along its length.

6. The consumable of any preceding claim, wherein an internal diameter of the outlet is at least 20% of a width of the tank.

7. The consumable of claim 6, wherein the tank has a width, as measured in the same direction as the internal diameter of the outlet, of at least 10 mm and no more than 20 mm.

8. The consumable of any preceding claim, wherein the outlet is fluidly connected at a first end to the heater assembly and fluidly connected at a second end to the mouthpiece, and wherein the cross-sectional area at the first end is more than 5mm².

9. The consumable of any preceding claim, further comprising a filter (302), disposed between the tank and an outlet of the mouthpiece, which is configured to be impermeable to unvapourised liquid and permeable to vapourised liquid.

10. The consumable of claim 9, wherein the filter is positioned in or adjacent to the mouthpiece.

11. The consumable of either claim 9 or claim 10, further including an air inlet (164), disposed at an opposite end of the consumable to the mouthpiece, and wherein the air inlet, heater assembly, and mouthpiece define a path for airflow through the consumable in that order.

12. The consumable of any of claims 9 - 11 , wherein the filter is formed from a fabric so as to be permeable to vapourised liquid but impermeable to unvapourised liquid.

13. The consumable of any of claims 9 - 11 , wherein the filter is formed from a mesh so as to be permeable to vapourised liquid but impermeable to unvapourised liquid.

14. The consumable of any of claims 9 - 11 , wherein the filter is a gas-permeable and liquid-impermeable membrane.

15. A smoking substitute device, including the consumable of any of claims 1 - 14.