Patent Application
20240365862
The present disclosure relates generally to a cartridge for a vapour generating device, for example an electronic cigarette or a personal vaporizer, configured to heat a vapour generating liquid to generate a vapour which cools and condenses to form an aerosol for inhalation by a user of the device. Embodiments of the present disclosure also relate to a vapour generating system comprising a vapour generating device and a cartridge configured for use with the vapour generating device. The present disclosure is particularly applicable to a cartridge for use with a portable (hand-held) vapour generating device.
The popularity and use of reduced-risk or modified-risk devices (also known as aerosol generating devices or vapour generating devices) has grown rapidly in recent years as an alternative to the use of traditional tobacco products. Various devices and systems are available that heat or warm a vapour generating substrate to generate a vapour which cools and condenses to form an aerosol for inhalation by a user.
Currently available vapour generating devices can use one of a number of different approaches to heat the vapour generating substrate, including resistive heating and induction heating. In the case of induction heating, the vapour generating device employs an electromagnetic field generator and an induction coil to generate an alternating electromagnetic field that couples with, and inductively heats, an inductively heatable susceptor. Heat from the inductively heatable susceptor is transferred to the vapour generating substrate to release one or more volatile components and generate a vapour.
In some vapour generating devices, the vapour generating substrate is a vapour generating liquid (or so called “e-liquid”), for example containing one or more of nicotine, propylene glycol, glycerine and flavourings. The vapour generating liquid can be transferred from a liquid store by a liquid transfer element, such as a wick, and is heated and vaporized by heat transferred from the inductively heatable susceptor, resulting in the generation of a vapour which cools and condenses to form an inhalable aerosol. The vapour generating liquid, liquid transfer element and inductively heatable susceptor can be provided together in a replaceable cartridge (cartomizer) that is configured for use with the vapour generating device.
Whilst the use of induction heating in vapour generating devices is efficient, currently available inductively heated vapour generating devices can suffer from a number of drawbacks which the present disclosure seeks to address.
According to a first aspect of the present disclosure, there is provided a cartridge for a vapour generating device, the cartridge comprising:
The cartridge is intended for use with a vapour generating device that is configured to heat the vapour generating liquid to volatise at least one component of the vapour generating liquid and thereby generate a vapour which cools and condenses to form an aerosol for inhalation by a user of the vapour generating device.
According to a second aspect of the present disclosure, there is provided a vapour generating system comprising a vapour generating device and a cartridge according to the first aspect releasably connected to the vapour generating device.
In general terms, a vapour is a substance in the gas phase at a temperature lower than its critical temperature, which means that the vapour can be condensed to a liquid by increasing its pressure without reducing the temperature, whereas an aerosol is a suspension of fine solid particles or liquid droplets, in air or another gas. It should, however, be noted that the terms ‘aerosol’ and ‘vapour’ may be used interchangeably in this specification, particularly with regard to the form of the inhalable medium that is generated for inhalation by a user.
By using an inductively heatable susceptor having a substantially cylindrical shape and by positioning the substantially cylindrical inductively heatable susceptor beneath the liquid store, a strong electromagnetic coupling is achieved with the generated electromagnetic field, in particular because the inductively heatable susceptor is positioned in the region of highest electromagnetic field concentration. This in turn provides for rapid and uniform heating of the inductively heatable susceptor to a desired temperature and, thus, rapid and uniform heating of the vapour generating liquid, thereby ensuring instant vaporization of the vapour generating liquid and ensuring reliable vapour generation. The energy efficiency of the vapour generating device is also improved. The coaxial arrangement of the inductively heatable susceptor with respect to the central longitudinal axis of the cartridge may also contribute to these advantageous effects because an optimum positioning of the inductively heatable susceptor with respect to the generated electromagnetic field (and hence a strong electromagnetic coupling) can be assured when the cartridge is connected to a vapour generating device. The coaxial arrangement may also facilitate manufacture and assembly of the cartridge because the inductively heatable susceptor can be easily positioned coaxially with respect to the central longitudinal axis of the cartridge.
The at least one channel or opening provides a reliable and efficient supply of the vapour generating liquid from the liquid store to the porous liquid transfer element.
This further contributes to reliable vapour generation by ensuring that a sufficient amount of vapour generating liquid is always available to be held and transferred by the porous liquid transfer element to the vaporization device, and more particularly the inductively heatable susceptor.
The porous liquid transfer element may be substantially cylindrical. The porous liquid transfer element may be toroidal. The at least one substantially cylindrical inductively heatable susceptor may have an axial length which is less than an axial length of an outer surface of the porous liquid transfer element. The term “axial length” means a length in the direction of the longitudinal axis of the cartridge.
The at least one substantially cylindrical inductively heatable susceptor may extend around an outer surface of the porous liquid transfer element, and in particular may extend around a radially outer surface of the porous liquid transfer element. Thus, the at least one substantially cylindrical inductively heatable susceptor is positioned outwardly, e.g., radially outwardly, of the porous liquid transfer element. This further ensures that the inductively heatable susceptor is positioned in the region of highest electromagnetic field concentration and, thus, further helps to ensure that a strong electromagnetic coupling is achieved with the generated electromagnetic field. In addition, mechanical stress on the porous liquid transfer element resulting from thermal expansion of the inductively heatable susceptor is substantially reduced or eliminated because the inductively heatable susceptor expands outwardly, away from the porous liquid transfer element, when it is inductively heated. The risk of damage, e.g., cracking, being caused to the porous liquid transfer element by the inductively heatable susceptor when it thermally expands is thereby correspondingly substantially reduced or eliminated. A further benefit of this arrangement is that the inductively heatable susceptor does not need to be fluid permeable (e.g., in the form of a mesh) because generated vapour does not need to pass through it to escape from the porous liquid transfer element.
The at least one substantially cylindrical inductively heatable susceptor may fully surround the outer surface of the porous liquid transfer element. By fully surrounding the outer surface of the porous liquid transfer element with the substantially cylindrical inductively heatable susceptor, an efficient and uniform transfer of heat, e.g., by conduction, from the substantially cylindrical inductively heatable susceptor to the porous liquid transfer element is achieved so that “hot spots” and “cold spots” are avoided. This in turn ensures that a sufficient amount of vapour is generated during use.
The at least one substantially cylindrical inductively heatable susceptor is desirably dimensioned such that uniform heat distribution is ensured over its surface area. This further ensures that an efficient and uniform transfer of heat, e.g., by conduction, from the substantially cylindrical inductively heatable susceptor to the porous liquid transfer element is achieved and that “hot spots” and “cold spots” are avoided.
A uniform transfer of heat from the inductively heatable susceptor to the porous liquid transfer element results in instantaneous vaporisation of the vapour generating liquid held and transferred by the porous liquid transfer element and avoids a build-up of vapour generating liquid which can cause over-saturation of parts of the porous liquid transfer element. An over-saturated porous liquid transfer element can lead to projections of vapour generating liquid spitting from the porous liquid transfer element when heated by the inductively heatable susceptor. These liquid projections can be unpleasant when a user inhales the generated vapour.
The at least one substantially cylindrical inductively heatable susceptor may include an inner surface that contacts the outer surface of the porous liquid transfer element. With this arrangement, there is no gap between the outer surface of the porous liquid transfer element and the inner surface of the substantially cylindrical inductively heatable susceptor. Thus, heat can be readily conducted from the inductively heatable susceptor to the porous liquid transfer element thereby improving vapour generation and energy efficiency.
The outer surface of the porous liquid transfer element may be substantially frusto-conical and the inner surface of the at least one substantially cylindrical inductively heatable susceptor may have a corresponding substantially frusto-conical shape. This may help to simplify the manufacture and assembly of the cartridge.
The at least one substantially cylindrical inductively heatable susceptor may comprise a susceptor ring. The at least one substantially cylindrical inductively heatable susceptor may comprise a plurality of susceptor rings which may be spaced along the central longitudinal axis of the cartridge. The at least one substantially cylindrical inductively heatable susceptor may comprise a susceptor tube. These substantially cylindrical susceptor geometries all provide for a strong electromagnetic coupling with the generated electromagnetic field and a uniform transfer of heat to the porous liquid transfer element.
The at least one substantially cylindrical inductively heatable susceptor may comprise an electrically conductive material and may comprise a metal. The metal is typically selected from the group consisting of stainless steel, mild steel and carbon steel, and may comprise a low carbon stainless steel. The inductively heatable susceptor could, however, comprise any suitable material including one or more, but not limited, of aluminium, iron, nickel, and alloys thereof, e.g. Nickel Chromium or Nickel Copper. With the application of an electromagnetic field in its vicinity during use of the cartridge in combination with a vapour generating device, the substantially cylindrical inductively heatable susceptor may generate heat due to eddy currents and/or magnetic hysteresis losses resulting in a conversion of energy from electromagnetic to heat.
The at least one substantially cylindrical inductively heatable susceptor may have a thickness up to 150 μm. The thickness may be between 30 μm and 150 μm. The thickness may be approximately 100 μm. An inductively heatable susceptor having these thickness dimensions may be particularly suitable for being inductively heated during use of the cartridge with a vapour generating device and may also facilitate manufacture of the cartridge.
The at least one channel or opening may be configured to provide a sufficient supply of vapour generating liquid from the liquid store to the porous liquid transfer element whilst limiting thermal energy transfer from the at least one substantially cylindrical inductively heatable susceptor and/or the porous liquid transfer element to the liquid store. By “sufficient supply of vapour generating liquid”, it is meant that the supply of vapour generating liquid is sufficient to achieve a uniform saturation of the porous liquid transfer element whilst substantially avoiding regions which are under-saturated or over-saturated. By limiting the transfer of thermal energy, i.e., heat propagation, from the inductively heatable susceptor and/or the porous liquid transfer element to the vapour generating liquid in the liquid store, i.e., by interrupting the thermal bridge, the energy efficiency of the vapour generating device is improved and thermal altering effects on the vapour generating liquid can be minimised or avoided.
The liquid store may comprise a sealing element which may be positioned at a distal end of the cartridge. The sealing element may comprise an elastomeric material, e.g., silicone. The sealing element ensures that the vapour generating liquid cannot escape from the liquid store. The sealing element may include the at least one channel or opening. The use of a sealing element comprising an elastomeric material may further help to limit the transfer of thermal energy, i.e., heat propagation, from the inductively heatable susceptor and/or the porous liquid transfer element to the vapour generating liquid in the liquid store.
The at least one channel or opening may extend obliquely with respect to the central longitudinal axis of the cartridge, for example through the sealing element. An efficient delivery of vapour generating liquid from the liquid store to the porous liquid transfer element is thereby achieved.
The porous liquid transfer element typically comprises a non-inductively heatable material, for example an electrically non-conductive and paramagnetic or diamagnetic material. Thus, the porous liquid transfer element is not itself inductively heated in the presence of an alternating electromagnetic field. The porous liquid transfer element may comprise a porous ceramic. The porous liquid transfer element may include a proximal end adjacent to the liquid store and an opposite distal end which may have a step. The porous liquid transfer element may have a conical or oval shape in cross-section.
In some embodiments, the cartridge may further comprise an induction coil which may surround the at least one substantially cylindrical inductively heatable susceptor. By providing the induction coil as an integral part of the cartridge, an optimum relative positioning of the induction coil and the at least one substantially cylindrical inductively heatable susceptor may be achieved. This in turn ensures that a strong electromagnetic coupling is achieved between the generated electromagnetic field and the inductively heatable susceptor.
In some embodiments, the vapour generating device may comprise an induction coil which may surround the at least one substantially cylindrical inductively heatable susceptor when the cartridge is connected to the vapour generating device. By providing the induction coil as an integral part of the vapour generating device, the manufacture and assembly of the cartridge may be simplified.
The induction coil may have a shape which substantially corresponds to the shape of the at least one substantially cylindrical inductively heatable susceptor. For example, the induction coil may be a helical coil.
The induction coil may comprise a Litz wire or a Litz cable. It will, however, be understood that other materials could be used.
The induction coil may be arranged to operate in use with a fluctuating electromagnetic field having a magnetic flux density of between approximately 20 mT and approximately 2.0 T at the point of highest concentration.
The vapour generating device may include circuitry. The power source and circuitry may be configured to operate at a high frequency. The power source and circuitry may be configured to operate at a frequency of between approximately 80 kHz and 500 kHz, possibly between approximately 150 kHz and 250 kHz, and possibly at approximately 200 kHz. The power source and circuitry could be configured to operate at a higher frequency, for example in the MHz range, depending on the type of inductively heatable susceptor that is used.
The cartridge may comprise a vapour outlet channel. The vaporization device may include a substantially cylindrical vaporization chamber which may be defined by the porous liquid transfer element. The substantially cylindrical vaporization chamber may be fluidly connected to the vapour outlet channel. Efficient vapour generation is thereby assured. In particular, a continuous process is achieved in which vapour generating liquid, e.g. from the liquid store, is continuously absorbed by the porous liquid transfer element and heated by the inductively heatable susceptor to generate a vapour in the vaporization chamber. Vapour generated during this process is transferred from the vaporization chamber via the vapour outlet channel in the cartridge so that it can be inhaled by a user of the vapour generating device/system.
The cartridge may comprise a mouthpiece. The mouthpiece may include an outlet which is in fluid communication with the vapour outlet channel. The mouthpiece may be integral with the liquid store and may be formed by a proximal end of the liquid store which may be tapered. The cartridge thus has a compact design. Manufacture and assembly of the cartridge is also simplified.
Alternatively, the vapour generating device may include a removable mouthpiece which may be releasably connectable to the vapour generating device. The cartridge may be configured for insertion into a cavity of the vapour generating device which may be closed when the mouthpiece is connected to the vapour generating device. The cartridge may be configured for insertion into a cavity formed within the mouthpiece which may be closed when the mouthpiece is connected to the vapour generating device.
The vapour generating liquid may comprise polyhydric alcohols and mixtures thereof such as glycerine or propylene glycol. The vapour generating liquid may contain nicotine. The vapour generating liquid may contain other additives and ingredients, such as flavourants. The term “vapour generating liquid” used herein includes any non-solid material, e.g. a semi-liquid material such as a gel or a wax, capable of generating a vapour when heated.
Embodiments of the present disclosure will now be described by way of example only and with reference to the accompanying drawings.
Referring initially to
The cartridge 10 comprises a cartridge housing 12 having a proximal end 14 and a distal end 16. The proximal end 14 may constitute a mouthpiece 18 and an outer wall 13 of the cartridge housing 12 may be tapered to facilitate introduction into a user's mouth. Thus, the proximal end 14 may also be designated as the mouth end. The cartridge 10 comprises a liquid store 20 configured for containing therein a vapour generating liquid.
The vapour generating liquid may comprise an aerosol-forming substance such as propylene glycol and/or glycerol and may contain other substances such as nicotine and acids. The vapour generating liquid may also comprise flavourings such as e.g. tobacco, menthol or fruit flavour. The liquid store 20 may extend generally between the proximal (mouth) end 14 and the distal end 16. The cartridge 10 also comprises a vapour outlet channel 22, and the liquid store 20 surrounds, and coextends with, the vapour outlet channel 22.
The cartridge 10 comprises first and second sealing elements 24, 26 at the distal end 16. The first and second sealing elements 24, 26 are configured to sealingly close off the distal end of liquid store 20 to retain the vapour generating liquid in the liquid store 20.
The first sealing element 24 comprises a first connecting portion 28a which is configured to sealingly connect to a distal end 22a of the vapour outlet channel 22. The first connecting portion 28a includes an annular flange 30 configured to seal against a radially outer surface 22b of the vapour outlet channel 22 at the distal end 22a.
The second sealing element 26 comprises a radially outer sealing surface 26a that contacts an inner surface 20a of the liquid store 20 at the distal end 16 of the cartridge housing 12. The second sealing element 26 also comprises a radially inner sealing surface 26b that contacts a radially outer sealing surface 24a of the first sealing element 24.
The first and second sealing elements 24, 26 may both be formed of a material with an elasticity that provides a sealing effect when the first connecting portion 28a of the first sealing element 24 is connected to the distal end 22a of the vapour outlet channel 22 and when the radially outer sealing surface 26a of the second sealing element 26 contacts the inner surface 20a of the liquid store 20. For example, the first and second sealing elements 24, 26 may comprise an elastomeric material such as silicone or rubber.
The cartridge 10 further comprises a vaporization device 36 and a porous liquid transfer element 38 at the distal end 16. The porous liquid transfer element 38 is positioned outside the inner volume of the liquid store 20, and more particularly beneath the liquid store 20. An advantage of this arrangement is that it allows the delivery of liquid to the porous liquid transfer element 38 to be carefully controlled whilst minimising heat transfer from the porous liquid transfer element to the vapour generating liquid in the liquid store 20.
The porous liquid transfer element 38 comprises a capillary material, typically a porous ceramic, and is positioned adjacent to channels or openings 40 formed in the first sealing element 24. A plurality of channels or openings 40 may be formed in the first sealing element 24 at circumferentially spaced positions. In the illustrated example, each channel or opening 40 extends obliquely with respect to a central longitudinal axis 11 of the cartridge 10. The channels or openings 40 connect the liquid store 20 to the vaporization device 36, and more particularly provide a controlled supply of vapour generating liquid from the liquid store 20 to the porous liquid transfer element 38 positioned beneath the liquid store 20 whilst minimising heat propagation from the porous liquid transfer element 38 to the vapour generating liquid in the liquid store 20.
The vaporization device 36 includes a heating element 42 in the form of an inductively heatable susceptor 44. The inductively heatable susceptor 44 is substantially cylindrical and in the illustrated example comprises a tubular susceptor. The inductively heatable susceptor 44 is positioned outside the inner volume of the liquid store 20, and more particularly beneath the liquid store 20. An advantage of this arrangement is that it enables a strong electromagnetic coupling to be achieved with a generated electromagnetic field during use of the vapour generating system 106.
The inductively heatable susceptor 44 is positioned outwardly of the porous liquid transfer element 38 and is arranged coaxially with respect to the central longitudinal axis 11. More particularly, the inductively heatable susceptor 44 fully surrounds the porous liquid transfer element and has an inner surface 46 that contacts an outer surface 48 of the porous liquid transfer element 38. As best seen in
As will be understood by one of ordinary skill in the art, when the inductively heatable susceptor 44 is exposed to an alternating and time-varying electromagnetic field generated by an electromagnetic field generator 108 of a vapour generating device 100 (see
In some examples, the electromagnetic field generator 108 includes an induction coil (not shown), for example a helical coil. Thus, the induction coil belongs to the vapour generating device 100 and is brought into proximity with (e.g., to surround) the inductively heatable susceptor 44 when the cartridge 10 is connected to the vapour generating device 100 via the releasable connection 110.
In some examples, the induction coil may be an integral part of, and belong to, the cartridge 10 and may surround the inductively heatable susceptor 44. An electrical connection may be established between the induction coil and the electromagnetic field generator 108 of the vapour generating device 100, for example via electrical connectors, when the cartridge 10 is connected to the vapour generating device 100 via the releasable connection 110.
The porous liquid transfer element 38 is toroidal and defines a substantially cylindrical, and centrally positioned, vaporization chamber 50 which is aligned with, and fluidly connected to, the vapour outlet channel 22 and in particular to the distal end 22a. The vaporization chamber 50 thus provides a route for vapour generated by heating the vapour generating liquid held and transferred by the porous liquid transfer element 38 to be transferred into the vapour outlet channel 22 where it cools and condenses to form an aerosol that can be inhaled by a user via the mouthpiece 18 at the proximal (mouth) end 14.
In operation of the vapour generating system 106, vapour generating liquid is conveyed from the liquid store 20 to the porous liquid transfer element 38 through the channels or openings 40 formed in the first sealing element 24. The vapour generating liquid is held and transferred by the porous liquid transfer element 38 (by capillary action) and is heated by the heat transferred to the porous liquid transfer element 38 from the inductively heatable susceptor 44. As noted above, when the cartridge 10 is used with a vapour generating device 100 including an electromagnetic field generator 108, the inductively heatable susceptor 44 is inductively heated by the electromagnetic field generated by the electromagnetic field generator 108 and the induction coil. The heat from the inductively heatable susceptor 44 is transferred to vapour generating liquid held and transferred by the porous liquid transfer element 38, resulting in the generation of a vapour. The vapour escapes from the porous liquid transfer element 38 into the vaporization chamber 50, and then flows from the vaporization chamber 50 along the vapour outlet channel 22 where it cools and condenses to form an aerosol that is inhaled by a user through the mouthpiece 18. The vaporization of the vapour generating liquid is facilitated by the addition of air from the surrounding environment through air inlets (not shown). The flow of air and/or vapour through the cartridge 10, i.e., through the vaporization chamber 50, along the vapour outlet channel 22, and out of the mouthpiece 18, is aided by negative pressure created by a user drawing air from the proximal (mouth) end 14 using the mouthpiece 18.
Although exemplary embodiments have been described in the preceding paragraphs, it should be understood that various modifications may be made to those embodiments without departing from the scope of the appended claims. Thus, the breadth and scope of the claims should not be limited to the above-described exemplary embodiments.
Any combination of the above-described features in all possible variations thereof is encompassed by the present disclosure unless otherwise indicated herein or otherwise clearly contradicted by context.
Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise”, “comprising”, and the like, are to be construed in an inclusive as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”.
| Number | Date | Country | Kind |
|---|---|---|---|
| 21187321.1 | Jul 2021 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/070341 | 7/20/2022 | WO |
