EP3923752B1 - Evaporator tank unit for an inhaler, preferably an electronic cigarette product, electronic cigarette product and wick structure - Google Patents

Description

The present invention relates to an evaporator-tank unit for an inhaler, preferably an electronic cigarette product, comprising at least one electrical evaporator for evaporating liquid supplied to the evaporator, a liquid reservoir for storing liquid, and a capillary wick structure, the liquid being expelled by capillary forces the liquid reservoir can be conveyed to an inlet side of the evaporator. The invention also relates to an inhaler, preferably an electronic cigarette product, and a wick structure.

Conventional electronic cigarette products or inhalers are based on wick coil technology. The liquid is transported from the liquid reservoir along a wick by capillary forces until the liquid is heated by an electrically heatable coil and thus vaporized. The wick serves as a liquid-conducting connection between the liquid reservoir and the heating coil serving as an evaporator.

A disadvantage of the wick-coil technology is that a lack of liquid supply leads to local overheating, which can lead to the formation of pollutants. This so-called "dry puff" should be avoided. In addition, such evaporator units are often leaky due to the manufacturing process, so that liquid can escape in an undesired manner, for example via the air inlet and/or vapor outlet.

In order to avoid the problems of the wick-coil technology, generic evaporators are used, which are based on the in DE 10 2017 111 119 A1 use disclosed technology. The liquid is transported by capillary forces from the wick structure from the liquid reservoir to the inlet side of the vaporizer, where the liquid is vaporized and vaporized liquid can be added to an air flow as vapor and/or aerosol.

A cylindrical wick structure is typically provided in the prior art, which on the one hand contacts the inlet side and on the other hand protrudes with an inlet end into the volume of the liquid reservoir.

However, if the liquid reservoir is no longer completely full, depending on the orientation of the inhaler, there may be a lack of liquid at the entry end of the wick structure, which leads to an interruption in the supply of liquid to the vaporizer.

Therefore, a voluminous sponge, cotton wool or the like is usually introduced into the liquid reservoir adjacent to the entry end of the wick structure as an intermediate storage of a certain transient supply amount of liquid. The sponge acts as a capillary buffer or intermediate conductor for liquid, so that the evaporator can be continuously supplied with liquid regardless of position and/or orientation and largely independent of the fill level.

The introduction of a sponge is complex in terms of production technology and can easily result in an insufficiently precise assembly poor fluid conduction between the sponge and the wicking structure, caused, for example, by the sponge not adequately contacting the wicking structure. The requirements for the dimensions of the liquid reservoir and the sponge and their assembly are therefore high.

Another relevant evaporator tank unit is in the Figures 6 to 8 from US2018/0020723A1 described. There, a reservoir with a wick element is designed in one piece as a "unitary reservoir and liquid transport element 454", with an extension also being formed in one piece as a "protrusion 464" and surrounded by a heating element "heating element 422" in the form of a heating coil.

It is the object of the invention to provide an evaporator-tank unit that enables the evaporator to be supplied with liquid effectively, reliably and independently of the orientation and/or the fill level of the liquid reservoir.

The object is solved by the features of independent claim 1.

According to the invention, it is proposed that the wick structure is in one piece and contacts and/or forms the liquid reservoir over at least one peripheral section. The integral nature of the wick structure avoids additional contact between a prior art sponge and a wick. The one-piece wick makes only one contact with the inlet side of the evaporator. A liquid-conducting contact between the inlet side of the evaporator and the wick structure can be reliably produced without bubbles or cavities being able to form, for example.

Contacting and/or forming the peripheral portion means that the wick structure can take up liquid from an area of the liquid reservoir and temporarily store it, even if the liquid reservoir is almost empty and the liquid temporarily moves away from the peripheral portion of the wick structure due to the force of gravity, since it is out of the wick structure once the liquid has been taken up, it is no longer released into the liquid reservoir becomes. It is therefore sufficient for sufficient intermediate storage if liquid now and then “spills” onto the wick structure and/or this can dip into the liquid. The wick structure can contact the peripheral portion of the liquid reservoir by the wick structure extending up to the peripheral portion, ie the wick structure protrudes into the liquid reservoir. The wick structure can form the liquid reservoir even more spacious, in that the wick structure occupies further areas of the liquid reservoir.

Preferably, the wick structure contacts the liquid reservoir along an inner surface of an outer wall of the liquid reservoir to allow the wick structure to absorb the liquid until the liquid reservoir is completely emptied. The wick structure may contact the inner surface of the outer wall with an interference fit. Alternatively, however, a gap may be provided that defines a minimum distance between the inner surface and the wick structure to simplify assembly of the wick structure.

The liquid reservoir preferably has a longitudinal axis, and the wick structure extends radially in at least two diametrical directions perpendicular to the longitudinal axis, so that the wick structure can absorb the liquid independently of the orientation of the liquid reservoir, in particular independently of the rotation of the liquid reservoir about the longitudinal axis of the liquid reservoir.

Preferably, an air duct extending through the liquid reservoir is provided in the liquid reservoir so that a effective construction of the evaporator tank unit can be made possible.

In an advantageous embodiment, the wicking structure has a plurality of diverging and/or opposed wicking sections contacting different peripheral sections to allow the wicking structure to absorb the liquid regardless of the orientation of the liquid reservoir. This enables contact with the liquid in opposite sections of the liquid reservoir and further prevents the wick structure and the evaporator from running dry.

According to the present invention, the wick structure has a U-shaped cross section with an apex and is arranged so that the wick structure contacts the inlet side at its apex to enable effective construction and easy assembly of the vaporizer tank unit.

Advantageously, the peripheral section has at least an angle of 45°, further advantageously at least 90°, particularly advantageously at least 180°, for example 270° and up to 360°, in order to promote a supply of liquid to the wick structure that is independent of orientation and fill level. The peripheral section can be continuous or can be formed from several separate subsections. For example, contact can be made and/or formed with two or more circumferential sections distributed uniformly in particular in the circumferential direction. In particular, two peripheral sections can be provided, each with an angle of 90°, which are spaced apart from one another, for example arranged diametrically opposite one another.

The wick structure preferably has a mechanical holder for holding the evaporator and/or a carrier.

The wick structure is preferably at least partially in the form of a hollow cylinder in order to be able to advantageously contact and/or form the peripheral surface of a cylindrical liquid reservoir. Liquid can be storable in the cavity. The cavity can form a large part of the volume of the liquid reservoir, for example at least 50%, preferably at least 70% and more preferably at least 90%.

The wick structure advantageously forms the liquid reservoir at least partially. The liquid reservoir can thus be in several parts, with the wick structure being able to form a cylindrical section of the liquid reservoir, for example. Further sections of the liquid reservoir can be formed by a plastic, for example. Different sections of the liquid reservoir can, for example, be glued and/or connected to one another with mechanical elements such as catches, lugs or clips.

The wick structure preferably forms an outer wall of the liquid reservoir in order to ensure a simple construction of the evaporator-tank unit and at the same time to promote a liquid supply to the wick structure that is independent of orientation and filling level.

The wick structure preferably extends, starting from the electric evaporator, into the liquid reservoir and has a pore volume per pore that increases with the distance from the evaporator, so that optimal liquid delivery to the Evaporator and at the same time a buffer storage of liquid in the wick structure is advantageously achieved.

Advantageously, the wick structure has a storage section and a feed section, and the volume of the storage section in the liquid reservoir is greater than the volume of the feed section adjacent to the evaporator, so that the wick structure can protrude into the liquid reservoir in areas remote from the evaporator and at the same time provide a preferred buffer effect Temporary storage of liquid can meet.

Preferably, the wick structure has a painted, coated, and/or liquid-tight surface to form a peripheral portion of the liquid reservoir that is sealed and impervious to liquid. This ensures that the wick structure can form or replace the outer wall of the liquid reservoir.

The wick structure preferably consists of a porous glass. In contrast to the prior art, the wick structure advantageously does not consist of a plurality of fibers between which cavities form for liquid transport and for liquid conduction. Rather, the wick structure comprises a porous solid. This can be made of porous ceramics, but is preferably made of porous glass. In particular consisting of a borosilicate glass or another oxidic glass. The blanks of the wick structure can be effectively produced with a pressing tool. A wide variety of spatial forms or geometries are therefore conceivable, with an air duct running in particular axially being provided inside an outer wall of the liquid reservoir in the interior of the liquid reservoir can be. The pore size and the distribution of the pores of the wick structure can be adjusted by pressing. In particular, a pore gradient and/or pore size gradient can be set, with the pore sizes decreasing from the liquid reservoir to the evaporator. The pore size can, for example, have a diameter of 0 to 500 μm, preferably from 10 nm to 100 μm. The use of a pressed glass for the wick structure makes production and handling easier than, for example, ceramic wick structures according to the prior art. The wick structure may also be made from a composite of porous materials, for example comprising sections of porous glass and sections of ceramic. The glass wick structure is particularly chemically inert and temperature-stable, which is particularly advantageous when it comes into contact with the evaporator.

The wick structure is advantageously colored and is visible from the outside in order to be able to monitor the fill level of the liquid reservoir and to increase the optical value of the evaporator-tank unit. For this purpose, the wick structure can be arranged inside a transparent housing of the liquid reservoir. Alternatively, the wick structure can form the liquid reservoir or the housing and be directly visible from the outside.

A wick structure for an inhaler, in particular an electronic cigarette product, is advantageously in one piece and consists of a porous glass in order to provide a wick structure that is particularly effective and versatile.

The invention is explained below on the basis of preferred embodiments with reference to the accompanying figures.

Fig. 1

eine schematische Ansicht eines Inhalators;

Fig. 2

einen perspektivischen Schnitt durch einen Verdampfer und schematisch eine Verdampfer-Tank-Einheit;

Fig. 3

eine Verdampfer-Tank-Einheit gemäß dem Stand der Technik;

Fig. 4

eine Verdampfer-Tank-Einheit mit einem Schwamm gemäß dem Stand der Technik;

Fig. 5

eine perspektivische Ansicht einer erfindungsgemäßen Verdampfer-Tank-Einheit;

Fig. 6

einen Schnitt durch eine VerdampferTank-Einheit und mehrere Ausführungsformen einer Dochtstruktur;

Fig. 7

eine perspektivische Ansicht einer Verdampfer-Tank-Einheit und mehrere Ausführungsformen einer Dochtstruktur; und

Fig. 8

eine Dochtstruktur und einen Schnitt durch eine Verdampfer-Tank-Einheit.

It only shows figure 5 an evaporator-tank unit in accordance with present claim 1, in particular comprising a wick structure with a U-shaped cross section; further shows in the figures:

1

a schematic view of an inhaler;

2

a perspective section through an evaporator and schematically an evaporator-tank unit;

3

a prior art evaporator-tank unit;

4

a prior art vaporizer tank unit with a sponge;

figure 5

a perspective view of an evaporator tank unit according to the invention;

6

a section through a vaporizer tank unit and several embodiments of a wick structure;

Figure 7

a perspective view of an evaporator-tank unit and several embodiments of a wick structure; and

8

a wick structure and a section through an evaporator tank unit.

figure 1 1 schematically shows an inhaler 10 or an electronic cigarette product. The inhaler 10 comprises a housing 11 in which an air duct 30 or vent is provided between at least one air inlet opening 231 and an air outlet opening 24 at a mouth end 32 of the cigarette product 10 . The mouth end 32 of the inhaler 10 designates this End at which the consumer pulls for the purpose of inhalation, thereby subjecting the inhaler 10 to a negative pressure and creating an air flow 34 in the air channel 30 .

The inhaler 10 advantageously consists of a base part 16 and an evaporator-tank unit 1, which comprises an evaporator 60 and a liquid reservoir 18, and can be designed in particular in the form of an exchangeable cartridge. The liquid reservoir 18 can be refilled by the user of the inhaler 10 . The air sucked in through the air inlet opening 231 is guided in the air duct 30 to the at least one evaporator 60 . The evaporator 60 is connected or can be connected to the liquid reservoir 18 in which at least one liquid 50 is stored. For this purpose, a porous and/or capillary, liquid-conducting wick structure 19 is advantageously arranged on an inlet side 61 of the evaporator 60 .

The vaporizer 60 vaporizes liquid 50 which is supplied to the vaporizer 60 from the liquid reservoir 18 by the wick structure 19 by means of capillary forces, and admits the vaporized liquid to the air flow 34 as an aerosol/vapor at an outlet side 64 .

The electronic cigarette 10 also includes an electrical energy store 14 and an electronic control device 15. The energy store 14 is usually arranged in the base part 16 and can in particular be an electrochemical disposable battery or a rechargeable electrochemical battery, for example a lithium-ion battery , be. The evaporator tank unit 1 is arranged between the energy store 14 and the mouth end 32 . The electronic control device 15 comprises at least one digital data processing device, in particular Microprocessor and/or microcontroller in the base part 16 (as in figure 1 shown) and/or in the evaporator tank unit 1.

A sensor, for example a pressure sensor or a pressure or flow switch, is advantageously arranged in the housing 11, wherein the control device 15 can determine on the basis of a sensor signal emitted by the sensor that a consumer pulls on the mouth end 32 of the cigarette product 10 in order to inhale. In this case, the control device 15 controls the evaporator 60 in order to add liquid 50 from the liquid reservoir 18 as an aerosol/vapor into the air flow 34 .

The at least one evaporator 60 is arranged in a part of the evaporator-tank unit 1 facing away from the mouth end 32 . Effective electrical coupling and activation of the evaporator 60 are thus possible. The air flow 34 advantageously leads through an air duct 30 running axially through the liquid reservoir 18 to the air outlet opening 24.

The liquid 50 to be metered that is stored in the liquid reservoir 18 is, for example, a mixture of 1,2-propylene glycol, glycerin, water, at least one flavor and/or at least one active substance, in particular nicotine. However, the specified components of the liquid 50 are not mandatory. In particular, flavorings and/or active substances, in particular nicotine, can be dispensed with.

The evaporator-tank unit 1 or cartridge or the base part 16 advantageously comprises a non-volatile data memory for storing information or parameters relating to the evaporator-tank unit 1 or cartridge. The data store can be part of the electronic control device 15 . Information on the composition of the liquid stored in the liquid reservoir 18, information on the process profile, in particular power/temperature control; data for condition monitoring or system testing, for example leak testing; Data relating to copy protection and protection against counterfeiting, an ID for unique identification of the evaporator tank unit 1 or cartridge, serial number, date of manufacture and/or expiry date, and/or number of puffs (number of inhalation puffs by the consumer) or the time of use are stored. The data memory is advantageously electrically connected or can be connected to the control device 15 .

In the inhaler 10 and/or in an external memory, which can be connected to the inhaler 10 in a suitable and known manner, at least temporarily, by means of communication technology, user-related data, in particular about smoking behavior, could also be stored and preferably also for control and Regulation of the inhaler can be used.

Additional ducts, in particular at least one secondary air duct 101, which meet the air duct 30 downstream of the evaporator 60, can ensure that the gas/aerosol mixture is mixed with fresh air from a secondary air flow 102 and/or regulate post-treatment and/or recondensation processes.

In figure 2 A perspective section through an evaporator 60 and an evaporator-tank unit 1 are shown schematically.

The evaporator-tank unit 1 comprises a block-shaped, preferably monolithic heating element or evaporator 60 preferably made of an electrically conductive material, in particular a semiconductor material, preferably silicon. It is not necessary for the entire evaporator 60 to be made of an electrically conductive material. For example, it may be sufficient for the surface of the evaporator 60 to be electrically conductive, for example metallic, coated or preferably suitably doped. In this case, the entire surface does not have to be coated; for example, metallic or preferably non-metallic or non-metallically clad metallic conductor tracks can be provided on a non-conductive or semi-conductive base body. It is also not absolutely necessary for the entire evaporator 60 to heat; it may be sufficient, for example, if a section or a heating layer of the evaporator 60 heats up in the area of the outlet side 64 .

The evaporator 60 is provided with a plurality of micro-channels or liquid channels 62 which connect an inlet side 61 of the evaporator 60 to an outlet side 64 of the evaporator 60 in a liquid-conducting manner.

The mean diameter of the liquid channels 62 is preferably in the range between 5 μm and 200 μm, more preferably in the range between 30 μm and 150 μm, even more preferably in the range between 50 μm and 100 μm. Due to these dimensions, a capillary effect is advantageously generated, so that liquid penetrating into a liquid channel 62 on the inlet side 61 rises through the liquid channel 62 until the liquid channel 62 is filled with liquid. The volume ratio of liquid channels 62 to evaporator 60, which can be referred to as the porosity of the evaporator 60, is for example in the range between 10% and 50%, advantageously in the range between 15% and 40%, more advantageously in the range between 20% and 30%, and is for example 25%.

The edge lengths of the surfaces of the evaporator 60 provided with liquid channels 62 are, for example, in the range between 0.5 mm and 3 mm, preferably between 0.5 mm and 1 mm. The dimensions of the surfaces of the evaporator 60 provided with liquid channels 62 can be, for example: 0.95 mm×1.75 mm or 1.9 mm×1.75 mm or 1.9 mm×0.75 mm. The edge lengths of the evaporator 60 can be, for example, in the range between 0.5 mm and 5 mm, preferably in the range between 0.75 mm and 4 mm, more preferably in the range between 1 mm and 3 mm. The area of the evaporator 60 (chip size) can be 1 mm×3 mm, 2 mm×2 mm or 2 mm×3 mm, for example.

The width b of the evaporator 60 (see figure 2 ) is preferably in the range between 1 mm and 5 mm, more preferably in the range between 2 mm and 4 mm, and is 3 mm, for example. The height h of the evaporator 60 (see figure 2 ) is preferably in the range between 0.05 mm and 1 mm, more preferably in the range between 0.1 mm and 0.75 mm, even more preferably in the range between 0.2 mm and 0.5 mm and is, for example, 0.3 mm. Even smaller evaporators 60 can be manufactured, provided and operated in a functional manner.

The number of liquid ducts 62 is preferably in the range between four and 1000. In this way, the heat input into the liquid ducts 62 can be optimized and a guaranteed high evaporation capacity and a sufficiently large vapor outlet surface can be realized.

The liquid channels 62 are arranged in a square, rectangular, polygonal, round, oval or other shaped array. The array can be in the form of a matrix with s columns and z rows, with s advantageously in the range between 2 and 50 and more advantageously in the range between 3 and 30 and/or z advantageously in the range between 2 and 50 and more advantageously in the range is between 3 and 30. In this way, an effective and easily manufacturable arrangement of the liquid channels 62 can be implemented with a guaranteed high evaporation capacity.

The cross-section of the liquid channels 62 can be square, rectangular, polygonal, round, oval or shaped differently and/or change in sections in the longitudinal direction, in particular increase, decrease or remain constant.

The length of one or each liquid channel 62 is preferably in the range between 100 μm and 1000 μm, more preferably in the range between 150 μm and 750 μm, even more preferably in the range between 180 μm and 500 μm and is 300 μm, for example. In this way, an optimal liquid intake and portion formation can be realized with a sufficiently good heat input from the evaporator 60 into the liquid channels 62 .

The distance between two liquid channels 62 is preferably at least 1.3 times the clear diameter of a liquid channel 62, the distance being related to the central axes of the two liquid channels 62. The distance can preferably be 1.5 to 5 times, more preferably 2 to 4 times, the inside diameter of a liquid channel 62 . In this way an optimal heat input into the evaporator 60 and a sufficiently stable arrangement and wall thickness of the liquid channels 62 can be implemented.

Due to the features described above, the evaporator 60 can also be referred to as a volume heater.

The evaporator-tank unit 1 comprises a carrier 4 with a through-opening 104 for the liquid-conducting connection of the evaporator 60 and a liquid reservoir 18. A wick structure 19 is arranged in the through-opening 104 for this purpose.

The inlet side 61 of the evaporator 60 is connected to the liquid reservoir 18 in a liquid-conducting manner via the wick structure 19 . The wick structure 19 serves to passively convey liquid 50 from the liquid reservoir 18 to the evaporator 60 by means of capillary forces. The wick structure 19 advantageously makes planar contact with the inlet side 61 of the evaporator 60 and covers all liquid channels 62 of the evaporator 60 on the inlet side. On the side opposite the evaporator 60, the wick structure 19 is connected to the liquid reservoir 18 in a liquid-conducting manner.

The wick structure 19 consists of porous and/or capillary material which, due to capillary forces, is able to passively transport a sufficient quantity of liquid evaporated by the evaporator 60 from the liquid reservoir 18 to the evaporator 60 to prevent the liquid channels 62 and the liquid ducts 62 from emptying to prevent problems arising.

The wick structure 19 advantageously consists of an electrically non-conductive material in order to avoid undesired heating of liquid to be avoided in the wick structure 19 by current flow. The wick structure 19 advantageously has a low thermal conductivity.

The wick structure 19 advantageously consists of a glass, in particular a pressed borosilicate glass. However, the wick structure 19 can be made of one or more of the following materials: cotton, cellulose, acetate, plastic foam, plastic sponge, glass fiber fabric, glass fiber ceramic, sintered ceramic, ceramic paper, aluminosilicate paper, metal foam, metal sponge, another heat-resistant, porous and/or capillary material with a suitable Production rate, or a composite of two or more of the aforementioned materials exist. In one embodiment, the wick structure 19 may comprise at least one of a ceramic fiber paper and a porous ceramic.

If the wick structure 19 consists of an electrically and/or thermally conductive material, between the wick structure 19 and the evaporator 60 there is advantageously an insulating layer made of an electrically and/or thermally insulating material, for example glass, ceramic or plastic, with extending through the insulating layer , Provided with the liquid channels 62 corresponding openings.

The volume of the wick structure 19 is preferably in the range of 1mm^3 to 10mm^3, more preferably in the range of 2mm^3 to 8mm^3, even more preferably in the range of 3mm^3 to 7mm^3 and is, for example, 5 mm^3. The volume of the wicking structure 19 can be equal to a majority of the volume of the liquid reservoir 18 .

The dimensions of the liquid reservoir 18 can be larger than the wick structure 19 . The wick structure 19 can partially form the liquid reservoir 18 . The wick structure 19 can be inserted into an opening of a housing of the liquid reservoir 18, for example. A plurality of evaporators 60 can also be assigned to a liquid reservoir 18 .

An advantageous volume of the liquid reservoir 18 is in the range between 0.1 ml and 5 ml, preferably between 0.5 ml and 3 ml, more preferably between 0.7 ml and 2 ml or 1.5 ml.

Evaporator-tank unit 1 is preferably connected and/or can be connected to a heating voltage source 71 that can be controlled by control device 15 and is connected to evaporator 60 via electrical lines 105a, 105b in a contact area on opposite edge sections 132a, 132b of evaporator 60, so that an electrical voltage Uh generated by the heating voltage source 71 leads to a current flow through the evaporator 60 . Because of the ohmic resistance of the electrically conductive evaporator 60 , the current flow leads to the evaporator 60 being heated and therefore to the evaporation of liquid contained in the liquid channels 62 . Vapor/aerosol generated in this way escapes from the liquid channels 62 on the outlet side 64 and is admixed with the air flow 34 . More precisely, when it detects an air flow 34 caused by the consumer pulling through the air duct 30, the control device 15 activates the heating voltage source 71, with the liquid in the liquid ducts 62 being driven out of the liquid ducts 62 in the form of vapor/aerosol by spontaneous heating.

A voltage curve Uh(t) adapted to the liquid mixture used is preferably stored in the data memory of the inhaler 10 . This makes it possible to specify the voltage curve Uh(t) adapted to the liquid used, so that the heating temperature of the evaporator 60, and thus also the temperature of the capillary liquid channels 62, can be controlled over the evaporation process in accordance with the known evaporation kinetics of the respective liquid, whereby optimum evaporation results can be achieved. The evaporation temperature is preferably in the range between 100°C and 400°C, more preferably between 150°C and 350°C, even more preferably between 190°C and 290°C.

The evaporator 60 can advantageously be produced from sections of a wafer using thin-film layer technology, which has a layer thickness of preferably less than or equal to 1000 μm, more preferably 750 μm, even more preferably less than or equal to 500 μm. Surfaces of the evaporator 60 can advantageously be hydrophilic. The outlet side 64 of the evaporator 60 can advantageously be microstructured or have microrecesses (micro grooves).

The evaporator-tank unit 1 is adjusted so that a liquid quantity preferably in the range between 1 μl and 20 μl, more preferably between 2 μl and 10 μl, even more preferably between 3 μl and 5 μl, typically 4 μl, is metered in per puff of the consumer . The evaporator-tank unit can preferably be adjustable with regard to the amount of liquid/vapor per puff, ie per puff duration from 1 s to 3 s.

The sequence of the evaporation process is explained below as an example.

In an initial state, the voltage source 71 or the energy store 14 for the heating process is switched off.

For evaporating liquid 50, the voltage source 14, 71 for the evaporator 60 is activated. The voltage Uh is set in such a way that the evaporation temperature in the evaporator 60 and thus in the liquid channels 62 is adapted to the individual evaporation behavior of the liquid mixture used. This prevents the risk of local overheating and the resulting formation of pollutants.

In particular, an undesired differential evaporation of a liquid mixture can also be counteracted or counteracted or such can be avoided. Otherwise, a liquid mixture could prematurely lose components due to different boiling temperatures in the course of a sequence of vaporization processes, in particular "puffs", before the reservoir 18 of the liquid 50 is completely empty, which can have undesirable effects during operation, such as the lack of consistency in the dosage for a user could drag, especially with a pharmaceutically active liquid.

As soon as an amount of liquid that corresponds to or is related to the volume of the liquid channels 62 has evaporated, the heating voltage source 71 is deactivated. Since the liquid properties and quantity are advantageously known exactly and the evaporator 60 has a measurable, temperature-dependent resistance has, this point in time can be determined or controlled very precisely.

After completion of the heating process, the liquid channels 62 are mostly or completely emptied. The heating voltage 71 is then kept switched off until the liquid channels 62 are filled up again by means of the replenishment of liquid through the wick structure 19 . As soon as this is the case, the next heating cycle can be started by switching on the heating voltage 71.

The control frequency of the evaporator 60 generated by the heating voltage source 71 is generally advantageously in the range from 1 Hz to 50 kHz, preferably in the range from 30 Hz to 30 kHz, even more advantageously in the range from 100 Hz to 25 kHz.

The frequency and the duty cycle of the heating voltage Uh for the evaporator 60 are advantageously adapted to the natural vibration or natural frequency of the bubble vibrations during bubble boiling. The period length 1/f of the heating voltage can therefore advantageously be in the range between 5 ms and 50 ms, more advantageously between 10 ms and 40 ms, even more advantageously between 15 ms and 30 ms and be 20 ms, for example. Depending on the composition of the evaporated liquid 50, frequencies other than those mentioned can be optimally adapted to the natural vibration or natural frequency of the bubble vibrations.

Furthermore, it has been shown that the maximum heating current generated by the heating voltage Uh is preferably no more than 7 A, more preferably no more than 6.5 A, even more preferably no more than 6 A and optimally in the range between 4A and 6A to ensure concentrated vapor while avoiding overheating.

The delivery rate of the wick structure 19 is in turn optimally adapted to the evaporation rate of the evaporator 60 so that sufficient liquid 50 can be delivered at any time and the area in front of the evaporator 60 is prevented from running empty.

The evaporator device 1 is preferably manufactured on the basis of MEMS technology, in particular from silicon, and is therefore advantageously a micro-electro-mechanical system.

According to what has been said above, a structure is advantageously proposed consisting of a Si-based evaporator 60 which is advantageously planar at least on the inlet side 61 and one or more underlying capillary structures 19 with advantageously different pore sizes. The wick structure 19 arranged directly on the inlet side 61 of the evaporator 60 prevents the formation of bubbles on the inlet side 61 of the evaporator 60, since gas bubbles prevent a further conveying effect and at the same time lead to (local) overheating of the evaporator 60 due to a lack of cooling by the liquid flowing in.

figure 3 shows an evaporator-tank unit 1 according to the prior art. The evaporator tank unit 1 comprises a liquid reservoir 18 for storing liquid 50, a carrier 4 and a wick structure 19. The carrier 4 holds an evaporator 60, not shown, which is connected to the wick structure 19 on an inlet side 61 of the evaporator 60 in a liquid-conducting manner . On an outlet side 64 of the inlet side 61 opposite

Evaporator 60, the evaporator 60 can admit the evaporated liquid 50 as vapor and/or aerosol to an air flow 34 flowing through an air duct 30.

However, the cylindrical wick structure 19 can be used as in figure 3 shown fall dry, ie the wick structure 19 may lack a supply of liquid 50 if the liquid reservoir 18 is not completely filled with liquid 50 and/or the evaporator tank unit 1 is oriented such that the liquid 50 breaks the wick structure by gravity 19 not reached. This can result in a lack of liquid at the evaporator 60 . Critical, for example, is the state in which the wick structure 19 is "up" when the inhaler 10 is horizontally oriented, but a residue of liquid 50 is only "down" in the liquid reservoir 18, as in figure 3 shown.

figure 4 1 shows an evaporator-tank unit 1 with a sponge 199 or an absorbent element, impregnated substrate or hydroscopic pad according to the prior art for reducing the risk of liquid starvation at the wick structure 19 and/or at the evaporator 60. The evaporator-tank unit 1 differs from the in figure 3 shown embodiments around the sponge 199. The sponge 199 is a component that is separate from the wick structure 19 and is connected to the wick structure 19 in a liquid-conducting manner. However, connecting the wick structure 19 and the sponge 199 is laborious and error-prone.

figure 5 shows a perspective view of an evaporator-tank unit 1 according to the invention. The evaporator-tank unit 1 comprises an evaporator 60, which is held by a carrier 4, a Liquid reservoir 18 for storing liquid 50 and a capillary wick structure 19, wherein liquid 50 can be conveyed from the liquid reservoir 18 to an inlet side 61 of the evaporator 60 by capillary forces.

The liquid reservoir 18 stores the liquid 50 in a volume delimited by an outer wall 182 . The liquid reservoir 18 or the outer wall 182 of the liquid reservoir 18 can consist of a plastic and/or a coated, lacquered and/or surface-treated glass, for example.

The liquid reservoir 18 has a longitudinal axis L. An air channel 30 extending through the liquid reservoir 18 runs along or parallel to the longitudinal axis L. The air channel 30 is arranged within the liquid reservoir 18 . The air channel 30 forms an inner wall 185 of the liquid reservoir 18 . The liquid reservoir 18 thus stores liquid 50 between the inner wall 185 or the air duct 30 and the outer wall 182. The air duct 30 can, for example, together with the carrier 4 or with parts of the carrier 4, as a one-piece evaporator insert, for example made of plastic, for insertion into the evaporator Tank unit 1 be formed.

The evaporator 60 has an outlet side 64 which is arranged in such a way that the evaporator 60 can add evaporated liquid 50 as vapor and/or aerosol to an air flow 34 flowing through the air duct 30 . For example, the outlet side 64 can face the air duct 30 or the longitudinal axis L of the liquid reservoir 18 if the evaporator 60, as shown here by way of example, is arranged at a radial distance from the longitudinal axis L.

Advantageously, the liquid reservoir 18 extends the longest along the longitudinal axis L. The liquid reservoir 18 has a rotational symmetry about the longitudinal axis L, at least in sections. In this exemplary embodiment, the liquid reservoir 18 has a rotationally symmetrical section between an end face and the carrier 4 .

The wick structure 19 is in one piece and is set up to supply liquid 50 to the evaporator 60 regardless of the orientation of the evaporator-tank unit 1 by the wick structure 19 contacting the liquid reservoir 18 via a peripheral section 180a, 180b of the liquid reservoir 18 . For this purpose, the wick structure 19 contacts the liquid reservoir 18 along an inner surface 181 of the outer wall 182 of the liquid reservoir 18. The contacting of the peripheral section 180a, 180b ensures that the wick structure 19 can absorb liquid 50 independently of the liquid level in the liquid reservoir 18 and can forward it to the evaporator 60 .

The wick structure 19 extends in two diametrical directions perpendicular to the longitudinal axis L. In this embodiment, the wick structure 19 extends from the evaporator 60 on the one hand upwards in this illustration and on the other hand downwards. The wick structure 19 has two separate wick sections 191a, 191b which contact different sub-sections of the peripheral section 180a, 180b. The wick sections 191a, 191b protrude in particular into different areas which are separate from one another of the liquid reservoir 18 and thus improve the supply of the evaporator 60 with liquid 50.

The wick structure 19 has a U-shaped or horseshoe-shaped cross section with an apex 190 . The wick structure 19 is arranged such that the wick structure 19 contacts the inlet side 61 of the evaporator 60 at its apex 190 . At the wick sections 191a, 191b remote from the apex 190 and separated from each other, the wick structure 19 contacts the liquid reservoir 18 in the peripheral section 180a, 180b. Due to the U-shape of the wick structure 19, the wick structure 19 can be formed far into the liquid reservoir 18 in that the free ends or wick sections 191a, 191b of the wick structure 19 that are remote from the apex 190 embrace the evaporator 60. As a result, a liquid-conducting connection of the evaporator 60 is also achieved with areas of the liquid reservoir 18 that are remote from the evaporator 60, without restricting the assembly capability.

In this embodiment, the peripheral section 180a, 180b has two coherent subsections, a first subsection being assignable to the first wick section 191a and a second subsection to the second wick section 191b. In this embodiment, the peripheral section 180a, 180b has an angle of more than 180°, for example approximately 270°. The wick structure 19 thus connects the inlet side 61 of the evaporator 60 with the liquid 50 stored in the liquid reservoir 18 in a liquid-conducting manner and independently of the orientation or the filling level of the liquid reservoir 18.

The wick structure 19 extends from the electrical evaporator 60 into the liquid reservoir 18 and has a pore volume per pore that increases with the distance from the evaporator 60 . The wick structure 19 comprises a storage section 184a and a feed section 184b, with the feed section 184 in particular being able to have smaller pores than the storage section 184a, which can serve as a liquid buffer. The supply section 184b is the section of the wick structure 19 which contacts the inlet side 61 of the evaporator 60 and which supplies the liquid 50 to the evaporator 60 . The storage section 184a is the section of the wick structure 19 that protrudes into the liquid reservoir 18. In this example, the storage section 184a is formed by the wick sections 191a, 191b or the free ends of the wick structure 19. The volume of the storage section 184a is greater than the volume of the supply section 184b adjacent to the evaporator 60 . The feed section 184b is arranged in the area of the apex 190 .

The wick structure has a mechanical support 192 . The mechanical mount 192 has in figure 5 shown embodiment different functions. The mechanical holder 192 can be used to attach the wick structure 19 to the carrier 4 . In this way, the wick structure 19 and/or the carrier 4 can be held in place by the wick structure 19 within the evaporator tank unit 1 in a non-displaceable manner. The holder 192 can be used to hold the evaporator 60 .

The wick structure 19 advantageously consists of a porous glass, for example a borosilicate glass. The wick structure 19 is advantageously colored in order to make it easier to see how full the liquid reservoir 18 is.

In figure 6 A section through an evaporator tank unit 1 and several embodiments of a one-piece wick structure 19 are shown. From left to right, the figure shows twice a wick structure 19 (a), (b), a wick structure 19 with an evaporator 60 (c) and an evaporator-tank unit 1 (d).

The left wick structure 19 in figure 6 (a) has a bone shape, ie the wick structure 19 comprises a centrally arranged feed section 184b and in this example two oppositely arranged wick sections 191a, 191b. In this example, the wick sections 191a, 191b are connected to one another only via the central feed section 184b. The wick sections 191a, 191b form two separate storage sections 184a. The wick structure 19 is thus set up to contact a liquid reservoir 18 in two separate peripheral sections 180a, 180b, see the evaporator-tank unit 1 in figure 6 (d) . In particular, the wick structure 19 has a round perimeter and can therefore contact a peripheral section 180a, 180b, preferably the inner surface 181, of a liquid reservoir 18 with a round cross section. In the assembled state, the inlet side 61 of the evaporator 60 contacts the central feed section 184b of the wick structure 19.

The wick structure 19 in Figure 6(b) has a ring shape, ie the wick structure 19 is disc-shaped. The wick structure 19 comprises a centrally arranged feed section 184b and in this example an annular wick section 191a, 191b which is connected by two oppositely arranged webs which run radially from the feed section 184b to the annular wick section 191a, 191b. is fluidly connected to the annular wick section 191a, 191b or storage section 184a. The wick sections 191a, 191b form a contiguous storage section 184a. The wick structure 19 is thus set up to contact a liquid reservoir 18 in a peripheral section 180a, 180b, see the evaporator-tank unit 1 in figure 6 (d) . In particular, the wick structure 19 has a round perimeter and can therefore contact a peripheral section 180a, 180b, preferably the inner surface 181 of a liquid reservoir 18 with a round cross section, over its entire circumference. In the assembled state, the inlet side 61 of the evaporator 60 contacts the central feed section 184b of the wick structure 19.

The wick structure 19 in Figure 6(b) has acentric openings or recesses that form a holder 192 of the wick structure 19 . The holder 192 can be used, for example, to hold a carrier 4 and/or to hold the wick structure 19 in the evaporator tank unit 1 . In this example, two recesses are provided, and any number can be provided, in particular 1, 3 to 10 recesses can be provided. The recesses are in the form of ring segments and can also be in the form of slots, for example.

The wick structure 19 with the evaporator 60 according to FIG figure 6 (c) includes those related to Figure 6(b) wick structure 19 explained. The inlet side 61 of the evaporator 60 contacts the supply section 184b of the wick structure 19 in a planar and liquid-conducting manner. The outlet side 64 of the evaporator 60 is arranged facing away from the wick structure 19 .

As shown in the section through the evaporator tank unit 1 in figure 6 (d) As can be seen, the wick structure 19 contacts a liquid reservoir 18 via at least two spaced-apart peripheral portions 180a, 180b when a bone-shaped wick structure 19 according to FIG figure 6 (a) is used. Alternatively, the wick structure 19 can contact the liquid reservoir 18 over the entire circumference in a peripheral section 180a, 180b if an annular wick structure 19 according to FIG Figure 6(b) is used.

An evaporator 60 contacts a feed portion 184b of the wick structure 19 with an inlet side 61 . An outlet side 64 of the evaporator 60 faces an air duct 30 . The evaporator is held by the carrier 4 .

figure 7 shows a perspective view of an evaporator tank unit 1 and embodiments of a wick structure 19. From left to right the figure shows two wick structures 19 (a), (b), one wick structure 19 with a carrier 4 (c) and one evaporator -Tank unit 1 (d).

In the Figures 7 (a) and 7 (b) Wick structures 19 shown are those referred to in FIG Figures 6 (a) and 6 (b) illustrated wick structures 19 in a different perspective.

The wick structure 19 with the carrier 4 according to figure 7 (c) shows that the carrier 4 is held in the holder 192 of the wick structure 19 . The carrier 4 is designed in such a way that it can be inserted into the openings forming the holder 192 and held there in a non-displaceable manner.

As in Figures 7 (c) and (d) shown, the carrier 4 can have electrical contacts 100, for example, which establish an electrical connection to the evaporator 60, so that the evaporator 60 can be electrically contacted and controlled by a part that is external to the evaporator-tank unit 1. figure 7 (d) shows the evaporator-tank unit figure 6 (d) in a different perspective. The liquid tank 18 forms the outer part of the evaporator-tank unit 1, which can be electrically connected to an external part, for example a base part 16 of an inhaler 10, by means of the electrical contacts 100.

figure 8 shows a wick structure 19 on the left and a section through an evaporator-tank unit 1 according to an embodiment on the right.

The wick structure 19 is partially in the form of a hollow cylinder with a longitudinal axis and has a radially extending feed section 184b on an end face 195 . The hollow-cylindrical wick structure 19 has a cavity 196 which can geometrically enclose and/or store liquid 50 in the liquid reservoir 18 .

The hollow-cylindrical wick structure 19 can, for example, make full contact with a cylindrical liquid tank 18 on a peripheral section 180a, 180b corresponding to an inner surface 181 of an outer wall 182 of the liquid reservoir 18 . In this embodiment, the wick structure 19 may be made entirely of a porous material. The wick structure 19 can be inserted into a liquid reservoir 18 and ensures that liquid 50 is in connection with the wick structure 19 regardless of the orientation or the fill level.

The wick structure 19 advantageously forms the liquid reservoir 18 . For this purpose, the wick structure 19 can have a liquid-tight outer wall 182 and thus form the outer wall 182 of the liquid reservoir 18 . A further component for storing liquid 50, which is separate from the wick structure 19 and forms the liquid reservoir 18, can thus be dispensed with.

For example, the wick structure 19 can be made of a porous and pressed glass. This allows the pore size and pore distribution to be set exactly. The supply section 184b may have a larger number of pores with a smaller volume per pore than the storage section 184a. The storage section 184 can also have a pore size gradient, with the pore size decreasing starting from the evaporator 60 and/or, for example, the pore size in the hollow-cylindrical section of the wick structure 19 being constant. By painting and/or coating, for example, the outer wall 182 of the wick structure 19 can be sealed to the outside in a liquid-tight manner and can produce the liquid reservoir 18 itself.

The wick structure 19 is advantageously colored in order, for example, to be able to recognize the filling level of the liquid reservoir 18 and/or to increase the visual value.

In this example, the evaporator 60 is oriented perpendicular to the longitudinal axis L with the inlet side 61 and an outlet side 64 . In other embodiments, however, the inlet side 61 and/or the outlet side 64 can also be parallel or at an angle to the longitudinal axis L aligned.

An air channel 30 is provided coaxially around the longitudinal axis L and preferably runs concentrically with the outer wall 182 of the liquid reservoir 18 .

Claims (14)

1. Vaporizer tank unit (1) for an electronic cigarette product (10), comprising

   - at least one electric vaporizer (60) for vaporizing liquid (50) supplied to the vaporizer (60)

   - a liquid reservoir (18) for storing liquid (50), and

   - a capillary wick structure (19), wherein the liquid (50) is conveyable by capillary forces from the liquid reservoir (18) to an inlet side (61) of the vaporizer (60), wherein

   - the wick structure (19) is one-piece and contacts the liquid reservoir (18) via at least one circumferential portion (180a, 180b) of the liquid reservoir (18) and/or forms a circumferential portion (180a, 180b) of the liquid reservoir (18), characterized in that

   - the wick structure (19) comprises a U-shaped cross-section with an apex (190) and is arranged such that the wick structure (19) contacts the inlet side (61) at its apex (190), wherein

   - the vaporizer (60) is provided with a plurality of fluid channels (62) fluidly connecting the inlet side (61) of the vaporizer (60) to an outlet side (64) of the vaporizer (60).
2. Vaporizer tank unit (1) according to any one of the preceding claims, characterized in that

   - the wick structure (19) contacts the liquid reservoir (18) along an inner surface (181) of an outer wall (182) of the liquid reservoir (18).
3. Vaporizer tank unit (1) according to any one of the preceding claims, characterized in that

   - the liquid reservoir (18) comprises a longitudinal axis (L), and the wick structure (19) extends radially in at least two diametrical directions perpendicular to the longitudinal axis (L).
4. Vaporizer tank unit (1) according to any one of the preceding claims, characterized in that

   - an air channel (30) extending through the liquid reservoir (18) is provided in the liquid reservoir (18).
5. Vaporizer tank unit (1) according to any one of the preceding claims, characterized in that

   - the wick structure (19) comprises a plurality of diverging and/or opposing wick sections (191a, 191b) contacting different circumferential portions (180a, 180b).
6. Vaporizer tank unit (1) according to any one of the preceding claims, characterized in that

   - the circumferential portion (180a, 180b) comprises at least an angle of 45°.
7. Vaporizer tank unit (1) according to any one of the preceding claims, characterized in that

   - the wick structure (19) comprises a mechanical retainer (192).
8. Vaporizer tank unit (1) according to any one of the preceding claims, characterized in that

   - the wick structure (19) is at least partially hollow cylindrical.
9. Vaporizer tank unit (1) according to any one of the preceding claims, characterized in that

   - the wick structure (19) extends from the electric vaporizer (60) into the liquid reservoir (18) and comprises a pore volume per pore that increases with distance from the vaporizer (60).
10. Vaporizer tank unit (1) according to any one of the preceding claims, characterized in that

    - the wick structure (19) comprises a storage section (184a) and a feed section (184b), and

    - the volume of the storage section (184a) in the liquid reservoir (18) is larger than the volume of the feed section (184b) adjacent to the vaporizer (60).
11. Vaporizer tank unit (1) according to any one of the preceding claims, characterized in that

    - the wick structure (19) comprises a painted, coated and/or liquid-tight surface (183).
12. Vaporizer tank unit (1) according to any one of the preceding claims, characterized in that

    - the wick structure (19) is made of a porous glass.
13. Vaporizer tank unit (1) according to any one of the preceding claims, characterized in that

    - the wick structure (19) is colored.
14. Electronic cigarette product (10) comprising a vaporizer tank unit (1) according to any one of the preceding claims.

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