AEROSOL GENERATOR
Amendments to the Specification This application is a National Stage Application of International Application No. PCT/RU2021/000327, filed Aug. 02, 2021, which claims priority to U.S. Provisional Application No. 63/060,697, filed Aug. 04, 2020, which is incorporated herein by reference. The present disclosure relates to an aerosol generating device comprising a source of electromagnetic field energy capable of heating and vaporizing a liquid medium to be aerosolized, and a liquid wicking capillary-porous member which is configured to substantially transmit the electromagnetic field energy thus allowing to eliminate generation of hazardous substances during the vaporization process.
This application claims priority of U.S. Provisional Application No. 63/060,697, filed Aug. 04, 2020, which is incorporated herein by reference.
FIELD OF THE INVENTIONThe present teachings generally relate to producing of human-consuming aerosol, and more particularly to aerosol generators, such as electronic cigarettes and similar by function inhalers utilizing heat induced vaporization.
BACKGROUNDIn the present aerosol generators, which utilize vaporization of a liquid medium, a liquid-saturated wick or a wick-like capillary-porous member is heated along with the liquid medium by an external heater element. When heating above the boiling point, hot vapor pockets having poor heat transfer rate arise in the liquid medium adjacent to the hot surfaces of the heating element and heated wick due to the Leidenfrost effect. The vapor pockets have low heat flux and cause hot spots and micro-explosions resulting in overheating and drying of the heater and capillary-porous member resulting in generation of the harmful compounds and substances that migrate into the user’s body when inhaled with aerosol.
SUMMARYThe present invention solves the technical problem of the vapor pockets associated with “hot surfaces” by selective internal heating of liquid media in capillary-porous members by electromagnetic field energy, so that the temperature of the capillary-porous member during the heating remains lower than the temperature of the liquid media.
The term “liquid medium” is used throughout the specification to refer to any liquid-state aerosol forming substance, for example, containing glycerin, propylene glycol, water, nicotine, flavors, alcohol.
The term “capillary-porous member” is used throughout the specification to refer to any structure or material having wicking properties, i.e. able to be saturated and transport a liquid medium keeping it from leaking due to the capillary forces. Examples of a capillary-porous member are a capillary, fibrous or/and open-pored spongy structures or/and materials.
There is therefore provided, in accordance with an embodiment of the invention, an aerosol-generating device utilizing electromagnetic field energy to heat and vaporize an aerosol forming liquid medium, comprising a capillary-porous member having a first surface permeable to a liquid medium, a second surface permeable to electromagnetic field energy, and a third surface permeable to a vapor of the liquid medium, and capable of wicking of a liquid medium in the direction from the first surface to the third surface beneath the second surface, wherein the capillary-porous member is transmissive for the electromagnetic field energy.
The use of “first”, “second,” etc. are only intended to distinguish the surfaces from each other and not to impart any order or hierarchy to the surfaces.
Typically, a material of the capillary-porous member may be made of aluminium oxide (Al2O3) compounds and titanium oxide (TiO2).
The third surface of the capillary-porous member may contain a second surface of the capillary-porous member.
In preferred embodiments the second surface of the capillary-porous member may be impermeable for a vapor of the liquid medium.
In other embodiments, the capillary-porous member may comprise plurality, preferably array, of micro-structures, for example, micro-posts and micro-nozzles, formed by the third surface on the capillary-porous member.
In an advantageous case the capillary-porous member is substantially transmissive to the electromagnetic field energy to which a liquid medium having thickness less than 1000 µm is substantially dissipative.
In other embodiments the aerosol-generating device utilizing electromagnetic field energy to heat and vaporize an aerosol forming liquid medium may comprise a liquid reservoir further comprising a liquid tank interfaced with the first surface of the capillary-porous member; and an electromagnetic field source further comprising an emitter faced to the second surface of the capillary-porous member configured to generate electromagnetic field with the energy selected so as to heat and vaporize the liquid medium.
The term “reservoir” is used throughout the specification to refer to any arrangement capable to store or contain liquid medium.
The term “source of electromagnetic field energy” is used throughout the specification to refer to any electrical arrangement comprising an electromagnetic field-emitting element or emitter and producing electromagnetic field energy by moving electrical charges in the emitter. The emitter of the electromagnetic field energy may comprise a laser, light emitting diode, lamp, magnetron, electrode. The electromagnetic field energy source may comprise field energy-forming means and/or arrangements, such as reflectors, lenses, waveguides, standing-wave resonators, configured electrodes.
In further embodiments, the aerosol-generating device utilizing electromagnetic field energy to heat and vaporize an aerosol forming liquid medium may comprise an air duct having inlet and outlet, containing at least one of the second and third surfaces of the heating body.
In a group of embodiment the capillary-porous member may be arranged and the electromagnetic field source may be configured to a pulse mode of vaporization generating a sequence of the pulses having a pulse duration and delay so that a temperature of the liquid medium repeatedly rises above a boiling point of the liquid medium during the pulse and falls below the boiling point during the delay between the pulses in the sequence of pulses
There is also provided, in accordance with embodiments of the invention, a method for aerosol generation, which include providing the aerosol-generating device comprising the capillary-porous member transmissive to the electromagnetic field energy; bringing the liquid medium into engagement with the first surface of the capillary-porous member; and generating electromagnetic field with the pulse energy selected so as to heat and vaporize the liquid medium. In accordance with some embodiments methods may include steps of directing air trough the air duct, detachment of capillary-porous member, the liquid tank and/or emitter. In accordance with other embodiments methods include generating a sequence of pulses of electromagnetic field having the pulse duration and delay in the range of 1 µs to 100 ms with the pulse energy selected so that a temperature of the liquid medium repeatedly rises above a boiling point of the liquid medium during the pulse and falls below the boiling point during the delay between the pulses in the sequence of pulses. The delay between the pulses in the sequence of pulse may be not shorter than the time for refilling of the liquid vaporized in the capillary-porous member by the pulse prior to the delay.
The present invention will be more fully understood from the following detailed description of the embodiments thereof, taken together with the drawings.
It would be beneficial to have a safe aerosol generator and method allowing aerosol generation at significantly reduced hazardous risk levels, as set forth in the following description.
Referring to
In accordance with the disclosed concept of selective heating, the capillary-porous member 12 substantially transmits the energy of the electromagnetic field energy 16 so that the electromagnetic field energy 16 increases the internal energy predominantly not in the material of the capillary-porous member 12, but in the liquid-medium 14 that may be retained within the capillary-porous structure of the capillary-porous member 12. Due to the refractions and scatterings introduced by the capillary-porous structure, the capillary-porous member 12 can be not necessarily transparent, even though made from a transparent material, but can be diffusively transmissive to the electromagnetic field energy 16. Under the conditions, the material of the capillary-porous member 12 can be less heatable than the liquid medium 14 when being exposed to the electromagnetic field energy 16.
In the embodiments, a capillary-porous member 12 is configured to transmit an electromagnetic field energy 16 which is dissipating in a liquid medium 14. For the concept of the selective heating according to the present invention it does not however matter by which specific physical mechanism the energy of an electromagnetic field energy 16 may be transformed into internal energy of a liquid medium 14 giving rise to the temperature of the liquid medium 14. For example (not shown), a capillary-porous member 12 may be configured to transmit an alternative electromagnetic field 16 that can be coupled into an electrically conductive or non-conductive liquid medium 14 giving rise to its temperature, for example, through the induction of Eddy currents or, for example, oscillations of dipolar molecules.
The capillary-porous member 12 can be formed by known from the art methods of fabrication of wicking structures like as, for example, fiber matrix, sponges, fabrics. The wicking structures hold the liquid medium 14 due to capillary forces but releases the vaporized liquid medium 14 when heated by the electromagnetic field energy 16 due to the drop in the liquid viscosity, capillary forces and pressure of the expanding vapor. The porous structure may have weight on the order of 100 g/m2, thickness exceeding 0.3 mm and be mechanical stable, similar to chemically inert high temperature ceramic or glass fiber filters known in the art. Such filters typically allow for liquid flow rates higher than that of cotton. The porosity of the capillary-porous member 12 may achieve 90% allowing liquid passage rate of the liquid medium 14 of at least about 3 µl/s·mm2, while withstanding pressure of at least 0.3 g/ mm2 in order to maintain integrity in the presence of hot gases in the pores of the capillary-porous member 12 .
As illustrated in
Illustrated in
Shown in
In other example, the micro-structures 1262 can be micro-nozzles formed by the third surface 126 in the direction inward the capillary-porous member 12 to promote aerosol formation. The term “micro-nozzle” is used throughout the specification to refer to a hollow device to control, particularly to direct and accelerate, a vapor of the liquid medium flowing through the micro-nozzle. Micro-nozzles 1262 can have varying cross sectional area and be cone-like profiled, as shown in
Illustrated in
The second surface 124 of the embodiments 20, 30 Illustrated in
Although not shown, other preferable embodiments may include a capillary-porous member 12 containing other aluminium oxide (Al2O3) compounds and/or titanium oxide (TiO2) having transmission window in the infrared range and a liquid medium 14 containing glycerol and/or propylene glycol dissipative in the range. The examples can be also expanded by the microwave range and electrically conductive liquids.
In further embodiments, the materials of a capillary-porous member 12 is configured to be transmissive not only in infrared, but also, for example, in microwave range thus providing selectivity of heating of a liquid medium 14.
It is further advantageous if a material of the capillary-porous member 12 is transmissive to the electromagnetic field energy 16 to which a liquid medium 14 having thickness less than 1000 µm is dissipative. In an example of embodiment example shown in
It is further preferable if a capillary-porous member 12 is configured to have its thermal relaxation time and refilling time shorter than the pulse delay δ. The thermal relaxation time and refilling rate of a capillary-porous member 12 are both associated with a pore size of the capillary-porous member 12. In most practical embodiments both the thermal relaxation time and refilling time can contain values in the range of about 1 µs to 100 ms in the case of a capillary-porous member 12 having pore size providing wicking effect to be in the range of 1 µm to 500 µm.
In a group of embodiments, for example, as illustrated in
In the group of embodiments shown in
A source of electromagnetic field energy 22 is an electrical arrangement comprising an electromagnetic field-emitting element or emitter 222 and producing electromagnetic field by moving electrical charges in the field-emitting element or emitter 222, shown in
In the embodiment 50 of
A liquid reservoir 18 can be detachable, for example, together an emitter 222. In other embodiments an emitter 222 can be itself detachable for a replacement.
In further embodiments an emitter 222 can be shielded to reduce the electromagnetic field in the space outside the capillary-porous member 12.
As Illustrated in
In the embodiments 10, 20, 30, shown in
In a group of preferred embodiments, as illustrated in
There is also provided, in accordance with embodiments of the invention, a method for aerosol generation, which include providing an aerosol generator comprising the capillary-porous member 12 transmissive for an electromagnetic field energy 16, for example, in the range 506, as shown in
The capillary-porous member 12 and/or emitter 222 and/or the reservoir 18 of an aerosol generator are detachable and thus capable to replacement. In accordance with the method, detachment of at least one of the items is also performed to replace it with another, for example new, item.
In further method, an aerosol generator also comprises an air duct 20. In accordance with the method, the air 146 is directed through the air duct 20, for example, when performing a puff.
In accordance with other method, the capillary-porous member 12 is arranged and the electromagnetic field source 22 is configured to a pulse mode of selective heating and vaporization. The driver 224 drives the emitter 222 to generate an electromagnetic field energy 16 in the form of a sequence of pulses 602, as shown in
The present invention is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the present invention includes both combinations and subcombinations of the various features described hereinabove, as well as variations and modifications thereof which would occur to persons skilled in the art upon reading the foregoing description and which are not disclosed in the prior art.
Claims
1-20. (canceled)
21. An aerosol generating device, comprising:
- a source of electromagnetic field energy capable of heating and vaporizing a liquid medium to be aerosolized; and
- a wicking capillary-porous member,
- wherein the capillary-porous member is configured to substantially transmit the electromagnetic field energy.
22. The device according to claim 21, wherein the capillary-porous member is made of aluminum oxide and/or titanium oxide.
23. The device according to claim 21, wherein the capillary-porous member has a first surface permeable to the liquid medium, a second surface permeable to the electromagnetic field energy, and a third surface permeable to the vapor of the liquid medium, and wherein the capillary-porous member is capable of wicking a liquid medium in the direction from the first surface to the third surface beneath the second surface.
24. The device according to claim 23, wherein the third surface of the capillary-porous member contains the second surface of the capillary-porous member.
25. The device according to claim 23, wherein the second surface of the capillary-porous member is impermeable to the vapor of the liquid medium.
26. The device according to claim 23, wherein the capillary-porous member comprises an array of micro-structures formed by the third surface to accelerate the vapor and/or enlarge the vapor ejection surface of the capillary-porous member.
27. The device according to claim 26, wherein the micro-structures are through micro-nozzles expanding from the second surface of the capillary-porous member.
28. The device according to claim 21, wherein the electromagnetic field energy is substantially dissipated in a layer of the liquid medium having thickness less than 1000 µm.
29. The device according to claim 23, comprising a liquid reservoir further comprising a liquid tank configured to contain a liquid medium interfaced with the first surface of the capillary-porous member; and an electromagnetic field source further comprising an emitter, emitting the electromagnetic fields energy toward the second surface of the capillary-porous member, configured to generate sufficient electromagnetic field energy to vaporize the liquid medium.
30. The device according to claim 29, wherein the emitter of the electromagnetic field source is comprised of at least one of the following emitting means: a laser, light emitting diode, lamp, magnetron, electrodes.
31. The device according to claim 29, wherein the electromagnetic field source comprises at least one of the following field-forming means or arrangements: reflector, lens, waveguide, standing-wave resonator, electrodes.
32. The device according to claim 29, wherein the emitter and the capillary-porous member with tank are separately detachable.
33. The device according to claim 29, further comprising an air duct having inlet and outlet, wherein the air duct contains at least one of the second and third surfaces of the capillary-porous member.
34. The device according to claim 29, wherein the electromagnetic field energy source is configurable to emit a sequence of the electromagnetic field energy pulses having duration and delay in the range of 1 µs to 100 ms correlated with the thermal relaxation time of the liquid medium in the pores of the capillary-porous member for vaporization in a pulsed mode.
35. A method for generation of aerosol comprising: providing the device according to claim 29; bringing the liquid medium into engagement with the first surface of the capillary-porous member; and generating electromagnetic field energy to initiate vaporization of the liquid medium.
36. A method for generation of aerosol comprising: providing the device according to claim 32; bringing the liquid medium into engagement with the first surface of the capillary-porous member; generating electromagnetic field energy to initiate vaporization of the liquid medium; and performing the detachment.
37. A method for generation of aerosol comprising: providing the device according to claim 33; bringing the liquid medium into engagement with the first surface of the capillary-porous member; generating electromagnetic field energy to initiate vaporization of the liquid medium; and directing air through the air duct.
38. A method for generation of aerosol comprising: providing the device according to claim 34; bringing the liquid medium into engagement with the first surface of the capillary-porous member; and generating the electromagnetic field energy in a sequence of pulses having duration and delay in the range of 1 µs to 100 ms correlated with the thermal relaxation time of the liquid medium in the pores of the capillary-porous member to initiate vaporization of the liquid medium in a pulse mode.
39. The method according to claim 38, wherein the delay between the pulses in the sequence of pulse is not shorter than the time for refilling of the liquid medium vaporized in the capillary-porous member by the pulse prior to the delay.
Type: Application
Filed: Aug 2, 2021
Publication Date: Nov 2, 2023
Inventor: Karen KALAYDZHYAN (Moscow)
Application Number: 18/040,160