EP3923752B2 - 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 electric evaporator for vaporizing liquid supplied to the evaporator, a liquid reservoir for storing liquid, and a capillary wick structure, wherein the liquid can be conveyed from the liquid reservoir to an inlet side of the evaporator by capillary action. 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. Capillary action draws the liquid from the reservoir along a wick until it is heated by an electrically heated coil and thus vaporized. The wick serves as the liquid-conducting connection between the reservoir and the heating coil, which acts as the vaporizer.

One disadvantage of wick-coil technology is that insufficient liquid supply can lead to local overheating, which can produce harmful substances. This so-called "dry puff" must be avoided. Furthermore, such evaporator units are often leaky due to manufacturing defects, allowing liquid to escape in undesirable ways, for example, through the air intake and/or vapor outlet.

To avoid the problems of wick-coil technology, generic vaporizers are used, which are based on the in DE 10 2017 111 119 A1 The technology revealed is used. In this process, the liquid is transported by capillary forces from the wick structure in the liquid reservoir to the inlet side of the evaporator, where the liquid is evaporated and the evaporated liquid can be added to an air stream as vapor and/or aerosol.

Typically, the prior art provides a cylindrical wick structure that contacts the inlet side on one side and extends into the volume of the liquid storage with an inlet end on the other.

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 inlet 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 similar material is typically inserted adjacent to the inlet end of the wick structure to serve as an intermediate reservoir for a certain amount of liquid. The sponge acts as a capillary reservoir or intermediate conductor for the liquid, ensuring that the evaporator can be continuously supplied with liquid regardless of its position, orientation, or fill level.

The insertion of a sponge is technically complex and can easily lead to insufficient fluid flow between the sponge and the wick structure due to insufficiently precise assembly. This can occur, for example, if the sponge does not make adequate contact with the wick structure. Therefore, the requirements for the dimensions of the fluid reservoir and the sponge, as well as their assembly, are 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 "unitary reservoir and liquid transport element 454", wherein an extension as "protrusion 464" is also molded in one piece and is enclosed by a heating element "heating element 422" in the form of a heating coil.

The object of the invention is to provide an evaporator-tank unit that enables an effective, reliable supply of liquid to the evaporator, independent of the orientation and/or fill level of the liquid storage.

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

According to the invention, it is proposed that the wick structure is a single piece and contacts the liquid reservoir over at least one circumferential section. The single-piece design of the wick structure eliminates the need for additional contact between a sponge, as described in the prior art, and a wick. The single-piece wick has contact only with the inlet side of the evaporator. A reliable, liquid-conducting contact between the inlet side of the evaporator and the wick structure can be established without the formation of, for example, bubbles or cavities.

Contact with the circumferential section allows the wick structure to absorb and temporarily store liquid from a portion of the liquid reservoir, even when the reservoir is nearly empty and the liquid temporarily moves away from the circumferential section of the wick structure due to gravity. This is because the liquid absorbed by the wick structure is not released back into the reservoir. Therefore, sufficient temporary storage is achieved if liquid occasionally spills over the wick structure and/or allows the wick structure to be immersed in the liquid. The wick structure can make contact with the circumferential section of the liquid reservoir by extending up to it, i.e., by projecting into the reservoir. The wick structure can even expand the liquid reservoir by occupying additional areas within it.

Preferably, the wick structure contacts the liquid reservoir along an inner surface of an outer wall of the reservoir, so that the wick structure can absorb the liquid until the reservoir is completely empty. The wick structure can contact the inner surface of the outer wall by means of an interference fit. Alternatively, a gap can be provided that defines a minimum distance between the inner surface and the wick structure to simplify assembly of the wick structure.

Preferably the liquid storage medium 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 regardless of the orientation of the liquid storage medium, in particular regardless of the rotation of the liquid storage medium about the longitudinal axis of the liquid storage medium.

Preferably, an air duct extending through the liquid storage tank is provided to enable an effective design of the evaporator-tank unit.

In an advantageous embodiment, the wick structure has several diverging and/or opposing wick sections that contact different circumferential sections, so that the wick structure can 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 invention, the wick structure has a U-shaped cross-section with a vertex and is arranged such that the wick structure contacts the inlet side at its vertex to enable an effective design and easy assembly of the evaporator tank unit.

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

Preferably, the wick structure has a mechanical holder for holding the evaporator and/or a support.

Preferably, the wick structure is at least partially hollow-cylindrical to advantageously contact the circumferential surface of a cylindrical liquid reservoir. Liquid can be stored in the cavity. The cavity can comprise a large proportion of the volume of the liquid reservoir, for example, at least 50%, preferably at least 70%, and more preferably at least 90%.

Advantageously, the wick structure forms at least part of the liquid reservoir. This allows the liquid reservoir to be multi-part, with the wick structure, for example, forming a cylindrical section. Further sections of the liquid reservoir can be formed from a plastic material. Different sections of the liquid reservoir can be bonded together and/or connected with mechanical elements such as latches, tabs, or clips.

Preferably, the wick structure forms an outer wall of the liquid storage unit to ensure a simple design of the evaporator-tank unit, while simultaneously promoting an orientation- and fill-level-independent liquid supply to the wick structure.

Preferably, the wick structure extends from the electric evaporator to the liquid storage 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 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 storage is larger than the volume of the feed section adjacent to the evaporator, so that the wick structure can extend into the liquid storage into areas far from the evaporator and at the same time fulfill a preferred buffering effect for the intermediate storage of liquid.

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

Preferably, the wick structure 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 for liquid transport and conduction are formed. Rather, the wick structure comprises a porous solid. This can consist of porous ceramic, but preferably of porous glass, in particular borosilicate glass or another type of glass. Oxide glass. The wick structure blanks can be efficiently produced using a pressing tool. This allows for a wide variety of spatial shapes and geometries, with a particularly axial air channel preferably being provided within an outer wall of the liquid reservoir. The pore size and distribution 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 size decreasing from the liquid reservoir towards the evaporator. The pore size can, for example, have a diameter of 0 to 500 µm, preferably from 10 nm to 100 µm. Using pressed glass for the wick structure makes production and handling simpler than, for example, ceramic wick structures according to the prior art. The wick structure can also consist of a composite of porous materials and, for example, comprise sections of porous glass and sections of ceramic. The wick structure made of glass is particularly chemically inert and temperature-stable, which is especially advantageous in contact with the evaporator.

Advantageously, the wick structure is colored and visible from the outside, allowing the fill level of the liquid reservoir to be monitored and enhancing the visual appeal of the evaporator-tank unit. For this purpose, the wick structure can be located inside a transparent housing of the liquid reservoir.

A wick structure for an inhaler, especially an electronic cigarette product, is advantageous if it is one-piece and made of porous glass to provide a particularly effective and versatile wick structure.

The invention is explained below with reference to preferred embodiments and 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.

This merely shows Figure 5 an evaporator tank unit in accordance with the present claim 1, in particular comprising a wick structure with a U-shaped cross-section; furthermore shown in the figures:

Fig. 1

a schematic view of an inhaler;

Fig. 2

a perspective section through an evaporator and a schematic representation of an evaporator-tank unit;

Fig. 3

an evaporator-tank unit according to the state of the art;

Fig. 4

an evaporator-tank unit with a sponge according to the state of the art;

Fig. 5

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

Fig. 6

a cross-section through an evaporator tank unit and several embodiments of a wick structure;

Fig. 7

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

Fig. 8

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

Figure 1 Figure 1 schematically shows an inhaler 10, or an electronic cigarette product. The inhaler 10 comprises a housing 11 in which an air channel 30, or chimney, 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 is the end at which the user draws to inhale, thereby creating a negative pressure in the inhaler 10 and generating an airflow 34 in the air channel 30.

The inhaler 10 advantageously consists of a base part 16 and a vaporizer-tank unit 1, which comprises a vaporizer 60 and a liquid reservoir 18, and can particularly be designed in the form of a replaceable cartridge. The liquid reservoir 18 can be refilled by the user of the inhaler 10. The air drawn in through the air inlet opening 231 is directed in the air duct 30 to the at least one vaporizer 60. The vaporizer 60 is connected or connectable 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 vaporizer 60.

The evaporator 60 evaporates liquid 50, which is supplied to the evaporator 60 from the liquid reservoir 18 by the wick structure 19 by means of capillary forces, and adds the evaporated liquid as an aerosol/vapor to the airflow 34 at an outlet side 64.

The electronic cigarette 10 further comprises an electrical energy storage device 14 and an electronic control device 15. The energy storage device 14 is generally arranged in the base part 16 and can, in particular, be a disposable electrochemical battery or a rechargeable electrochemical battery, for example, a lithium-ion battery. The vaporizer tank unit 1 is arranged between the energy storage device 14 and the mouthpiece 32. The electronic control device 15 comprises at least one digital data processing device, in particular a microprocessor and/or microcontroller, in the base part 16 (as shown in Figure 1). Figure 1 shown) and/or in the evaporator tank unit 1.

Advantageously, a sensor, for example a pressure sensor or a pressure or flow switch, is arranged in the housing 11, wherein the control device 15 can determine, on the basis of a sensor signal output by the sensor, that a consumer is at the mouth end 32 of the cigarette product 10 inhaling. In this case, the control device 15 activates the vaporizer 60 to add liquid 50 from the liquid reservoir 18 as an aerosol/vapor into the airflow 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. This enables effective electrical coupling and control of the evaporator 60. The airflow 34 advantageously leads through an air channel 30 running axially through the liquid reservoir 18 to the air outlet opening 24.

The liquid 50 stored in the liquid reservoir 18, which is to be dosed, is, for example, a mixture of 1,2-propylene glycol, glycerin, water, at least one flavoring and/or at least one active ingredient, in particular nicotine. However, the specified components of the liquid 50 are not mandatory. In particular, flavorings and/or active ingredients, especially nicotine, can be omitted.

The evaporator tank unit 1 or cartridge, or the base part 16, advantageously comprises a non-volatile data storage device for storing information or parameters relating to the evaporator tank unit 1 or cartridge. The data storage device can be part of the electronic control device 15. The data storage device advantageously contains 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 anti-counterfeiting measures, an ID for the 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 inhalations by the consumer) or the usage time. The data storage device is advantageously electrically connected to, or connectable to, the control device 15.

In the inhaler 10 and/or in an external storage device that can be connected to the inhaler 10 in a suitable and known manner, at least temporarily, via communication technology, user-related data, in particular about smoking behavior, could also be stored and preferably also used for controlling and regulating the inhaler.

Additional channels, in particular at least one secondary air channel 101, which meet the air channel 30 downstream of the evaporator 60, can ensure mixing of the gas/aerosol mixture with fresh air from a secondary air stream 102 and/or control post-treatment and/or recondensation processes.

In Figure 2 Figure 1 shows a perspective section through an evaporator 60 and a schematic representation of an evaporator-tank unit 1.

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, coated with a metallic material or preferably suitably doped. In this case, it is not necessary for the entire surface to be coated; for example, metallic or, preferably, non-metallic or non-metallically laminated metallic conductor tracks may be provided on a non-conductive or semiconducting substrate. It is also not essential for the entire evaporator 60 to heat up; for example, it may be sufficient if a section or heating layer of the evaporator 60 in the region of the outlet side 64 heats up.

The evaporator 60 is provided with a plurality of microchannels or liquid channels 62, which connect an inlet side 61 of the evaporator 60 with 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, and 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 entering a liquid channel 62 at the inlet side 61 rises upwards 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%, even 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 of 0.5 mm to 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 x 1.75 mm, 1.9 mm x 1.75 mm, or 1.9 mm x 0.75 mm. The edge lengths of the evaporator 60 can be, for example, in the range of 0.5 mm to 5 mm, preferably in the range of 0.75 mm to 4 mm, and more preferably in the range of 1 mm to 3 mm. The surface area of the evaporator 60 (chip size) can be, for example, 1 mm x 3 mm, 2 mm x 2 mm, or 2 mm x 3 mm.

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, for example, 3 mm. 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, preferably even further 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 functionally.

The number of liquid channels 62 is preferably in the range between four and 1000. In this way, the heat input into the liquid channels 62 can be optimized and a reliably high evaporation performance as well as a sufficiently large vapor outlet area can be achieved.

The liquid channels 62 are arranged in the form of a square, rectangular, polygonal, round, oval, or other shaped array. The array can be configured as a matrix with s columns and z rows, where s is advantageously in the range of 2 to 50 and further advantageously in the range of 3 to 30, and/or z is advantageously in the range of 2 to 50 and further advantageously in the range of 3 to 30. In this way, an effective and easily manufactured arrangement of the liquid channels 62 with a guaranteed high evaporation rate can be realized.

The cross-section of the liquid channels 62 can be square, rectangular, polygonal, round, oval or otherwise shaped, and/or change section by section 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, and even more preferably in the range between 180 µm and 500 µm, and is, for example, 300 µm. In this way, optimal liquid uptake and portioning can be achieved with 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 one liquid channel 62, the distance being measured along the central axes of the two liquid channels 62. The distance can preferably be 1.5 to 5 times, and more preferably 2 to 4 times, the clear diameter of one liquid channel 62. This ensures optimal heat input into the evaporator 60 and a sufficiently stable arrangement and wall thickness of the liquid channels 62.

Due to the aforementioned characteristics, the evaporator 60 can also be referred to as a volume heater.

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

The inlet side 61 of the evaporator 60 is connected to the liquid reservoir 18 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 action. The wick structure 19 advantageously makes full 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 via a liquid-conducting connection.

The wick structure 19 consists of porous and/or capillary material which, due to capillary forces, is able to passively replenish sufficient quantities of liquid evaporated by the evaporator 60 from the liquid reservoir 18 to the evaporator 60 in order to prevent the liquid channels 62 from running dry and the problems arising therefrom.

The wick structure 19 is advantageously made of an electrically non-conductive material to prevent unwanted heating of the liquid within the wick structure 19 due to current flow. The wick structure 19 advantageously exhibits low thermal conductivity.

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

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

The volume of the wick structure 19 is preferably in the range between 1 mm³ and 10 mm³, more preferably in the range between 2 mm³ and 8 mm³, and even more preferably in the range between 3 mm³ and 7 mm³, and is, for example, 5 mm³. The volume of the wick structure 19 can be equal to a large proportion of the volume of the liquid reservoir 18.

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

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.

The evaporator-tank unit 1 is preferably connected to and/or connectable to a heating voltage source 71, which is controllable by the control device 15 and is connected to the evaporator 60 via electrical leads 105a, 105b in a contact area at opposite edge sections 132a, 132b of the evaporator 60, such that an electrical voltage Uh generated by the heating voltage source 71 leads to a current flow through the evaporator 60. Due to the ohmic resistance of the electrically conductive evaporator 60, the current flow leads to heating of the evaporator 60 and therefore to evaporation of the liquid contained in the liquid channels 62. The vapor/aerosol generated in this way escapes from the liquid channels 62 to the outlet side 64 and is mixed with the airflow 34. More precisely, when an airflow 34 caused by the consumer pulling through the air duct 30 is detected, the control device 15 activates the heating voltage source 71, whereby the liquid located in the liquid channels 62 is driven out of the liquid channels 62 in the form of vapor/aerosol by spontaneous heating.

Preferably, the data memory of the inhaler 10 stores a voltage curve Uh(t) adapted to the liquid mixture used. This makes it possible to predefine the voltage profile Uh(t) according to the liquid used, so that the heating temperature of the vaporizer 60, and thus also the temperature of the capillary liquid channels 62, can be controlled over time during the vaporization process according to the known vaporization kinetics of the respective liquid, thereby achieving optimal vaporization results. The vaporization temperature is preferably in the range between 100 °C and 400 °C, more preferably between 150 °C and 350 °C, and even more preferably between 190 °C and 290 °C.

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

The vaporizer-tank unit 1 is set such that a quantity of liquid, preferably in the range of 1 µl to 20 µl, more preferably between 2 µl and 10 µl, and even more preferably between 3 µl and 5 µl, typically 4 µl, is dosed per puff by the consumer. Preferably, the vaporizer-tank unit can be adjusted with respect to the quantity of liquid/vapor per puff, i.e., per puff duration of 1 s to 3 s.

The following is an example of how the evaporation process works.

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

To evaporate liquid 50, the voltage source 14, 71 is activated for the evaporator 60. The voltage Uh is adjusted so 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, undesirable differential vaporization of a liquid mixture can be counteracted or prevented. Otherwise, a liquid mixture could prematurely lose components due to differing boiling points during a series of vaporization processes, especially "puffs," before the reservoir 18 of the liquid 50 is completely empty. This could lead to undesirable effects during operation, such as inconsistent dosing for the user, especially with a pharmaceutically active liquid.

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

After the heating process is complete, the liquid channels 62 are mostly or completely empty. The heating voltage 71 is then kept off until the liquid channels 62 are refilled by means of liquid being supplied 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 of 1 Hz to 50 kHz, preferably in the range of 30 Hz to 30 kHz, and even more advantageously in the range of 100 Hz to 25 kHz.

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

Furthermore, it has been shown that the maximum heating current generated by the heating voltage Uh should preferably not exceed 7 A, more preferably not exceed 6.5 A, and even more preferably not exceed 6 A, and should ideally be in the range between 4 A and 6 A to ensure concentrated steam 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 supplied at all times and the area in front of the evaporator 60 is not allowed to run dry.

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

Based on the foregoing, a structure is advantageously proposed consisting of a silicon-based evaporator 60, which is preferably planar at least on the inlet side 61, and one or more capillary structures 19 located underneath it, 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 inhibit further conveying and simultaneously lead to (local) overheating of the evaporator 60 due to a lack of cooling by the incoming liquid.

Figure 3 Figure 1 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 support 4, and a wick structure 19. The support 4 holds an evaporator 60 (not shown), which is connected to the wick structure 19 via a liquid-conducting connection at an inlet side 61 of the evaporator 60. At an outlet side 64 opposite the inlet side 61 of the evaporator 60, the wick structure 19 is connected via a liquid-conducting connection.

The evaporator 60 can add the evaporated liquid 50 as vapor and/or aerosol to an airflow 34 flowing through an air duct 30.

However, the cylindrical wick structure 19 can be used as in Figure 3 As shown, the wick structure 19 may run dry, i.e., it may lack a supply of liquid 50 if the liquid reservoir 18 is not completely filled with liquid 50 and/or the vaporizer-tank unit 1 is oriented in such a way that the liquid 50 does not reach the wick structure 19 due to gravity. This can result in a liquid shortage at the vaporizer 60. A critical situation arises, for example, when the wick structure 19 is located "at the top" with the inhaler 10 in a horizontal orientation, but some liquid 50 remains only "at the bottom" in the liquid reservoir 18, as shown in Figure 3 depicted.

Figure 4 Figure 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 shortage at the wick structure 19 and/or at the evaporator 60. The evaporator-tank unit 1 differs from the one shown in Figure 1. Figure 3 The embodiments shown are arranged around the sponge 199. The sponge 199 is a component separate from the wick structure 19, which is connected to the wick structure 19 in a fluid-conducting manner. However, connecting the wick structure 19 and the sponge 199 is complex and prone to errors.

Figure 5 Figure 1 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 support 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 storage unit 18 stores the liquid 50 in a volume bounded by an outer wall 182. The liquid storage unit 18, or the outer wall 182 of the liquid storage unit 18, can be made, for example, of a plastic and/or coated, painted and/or surface-treated glass.

The liquid storage tank 18 has a longitudinal axis L. An air duct 30 extends through the liquid storage tank 18 along or parallel to the longitudinal axis L. The air duct 30 is located inside the liquid storage tank 18. The air duct 30 forms an inner wall 185 of the liquid storage tank 18. Thus, the liquid storage tank 18 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, be configured together with the support 4 or with parts of the support 4 as a one-piece evaporator insert, for example made of plastic, for insertion into the evaporator-tank unit 1.

The evaporator 60 has an outlet side 64, which is arranged such that the evaporator 60 can add vaporized liquid 50 as vapor and/or aerosol to an airflow 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 storage tank 18 if the evaporator 60 is arranged radially spaced from the longitudinal axis L, as shown here by way of example.

The fluid reservoir 18 is advantageously most extensive along the longitudinal axis L. The fluid reservoir 18 exhibits rotational symmetry about the longitudinal axis L, at least in sections. In this embodiment, the fluid reservoir 18 has a rotationally symmetric section between an end face and the support 4.

The wick structure 19 is a single unit and is designed to supply liquid 50 to the evaporator 60 regardless of the orientation of the evaporator-tank unit 1. This is achieved by the wick structure 19 contacting the liquid reservoir 18 via a circumferential section 180a, 180b of the liquid reservoir 18. Specifically, the wick structure 19 contacts the liquid reservoir 18 along an inner surface 181 of the outer wall 182 of the liquid reservoir 18. This contact via the circumferential section 180a, 180b ensures that the wick structure 19 can absorb liquid 50 and transfer it to the evaporator 60 regardless of the liquid level in the liquid reservoir 18.

The wick structure 19 extends in two diametrically opposed directions perpendicular to the longitudinal axis L. In this embodiment, the wick structure 19 extends upwards and downwards from the evaporator 60, as shown in this illustration. The wick structure 19 comprises two separate wick sections 191a and 191b, which contact different subsections of the circumferential section 180a and 180b. The wick sections 191a and 191b project into different, separate areas of the liquid reservoir 18, thereby improving the supply of liquid 50 to the evaporator 60.

The wick structure 19 has a U-shaped or horseshoe-shaped cross-section with a vertex 190. The wick structure 19 is arranged such that at its vertex 190, it contacts the inlet side 61 of the evaporator 60. At the wick sections 191a, 191b, which are located away from and separate from the vertex 190, the wick structure 19 contacts the liquid reservoir 18 in the circumferential section 180a, 180b. Due to the U-shape of the wick structure 19, it can extend far into the liquid reservoir 18 by having the free ends or wick sections 191a, 191b of the wick structure 19, located away from the vertex 190, embrace the evaporator 60. This achieves a liquid-conducting connection between the evaporator 60 and areas of the liquid storage tank 18 located away from the evaporator 60, without restricting the assembly capability.

In this embodiment, the circumferential section 180a, 180b has two interconnected subsections, a first subsection corresponding to the first wick section 191a and a second subsection corresponding to the second wick section 191b. In this embodiment, the circumferential section 180a, 180b has an angle greater than 180°, for example, approximately 270°. Thus, the wick structure 19 connects the inlet side 61 of the evaporator 60 to the liquid 50 stored in the liquid reservoir 18 in a liquid-conducting manner, independent of the orientation or fill level of the liquid reservoir 18.

The wick structure 19 extends from the electric evaporator 60 into the liquid reservoir 18 and has a pore volume per pore that increases with distance from the evaporator 60. The wick structure 19 comprises a storage section 184a and a feed section 184b, whereby the feed section 184 can have smaller pores than the storage section 184a, which can serve as a liquid buffer. The feed section 184b is the section of the wick structure 19 that contacts the inlet side 61 of the evaporator 60 and supplies the liquid 50 to the evaporator 60. The storage section 184a is the section of the wick structure 19 that projects into the liquid reservoir 18. In this example, the storage section 184a is formed by the wick sections 191a and 191b, respectively, and the free ends of the wick structure 19. The volume of storage section 184a is larger than the volume of feed section 184b adjacent to evaporator 60. Feed section 184b is located in the region of the apex 190.

The wick structure features a mechanical holder 192. The mechanical holder 192 has in the Figure 5 The illustrated embodiment has various functions. The mechanical holder 192 can serve to attach the wick structure 19 to the support 4. This allows the wick structure 19 and/or the support 4 to be held securely against displacement within the evaporator-tank unit 1. The holder 192 can also serve to support the evaporator 60.

The wick structure 19 is advantageously made of a porous glass, for example, borosilicate glass. The wick structure 19 is advantageously colored to improve the visibility of the fill level of the liquid reservoir 18.

In Figure 6 Figure 1 shows a cross-section through an evaporator-tank unit 1 and several embodiments of a one-piece wick structure 19. From left to right, the figure shows two wick structures 19 each (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) The wick structure 19 has a bone-like shape, meaning it comprises a centrally arranged feed section 184b and, in this example, two oppositely arranged wick sections 191a and 191b. The wick sections 191a and 191b are connected to each other only via the central feed section 184b. The wick sections 191a and 191b form two separate storage sections 184a. Thus, the wick structure 19 is configured to contact a liquid storage reservoir 18 in two separate circumferential sections 180a and 180b, as shown in the evaporator-tank unit 1 in [reference missing]. Figure 6 (d) In particular, the wick structure 19 has a circular circumference and can therefore contact a circumferential section 180a, 180b, preferably the inner surface 181 of a liquid reservoir 18 with a circular 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) The wick structure 19 has a ring shape, i.e., it 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 fluid-conductingly connected to the annular wick section 191a, 191b, or storage section 184a, by two oppositely arranged webs extending radially from the feed section 184b to the annular wick section 191a, 191b. The wick sections 191a, 191b form a continuous storage section 184a. Thus, the wick structure 19 is configured to contact a liquid storage reservoir 18 in circumferential sections 180a, 180b, as shown in the evaporator-tank unit 1 in [reference missing]. Figure 6 (d) In particular, the wick structure 19 has a circular circumference and can therefore fully contact a circumferential section 180a, 180b, preferably the inner surface 181 of a liquid reservoir 18 with a circular 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) The device features asymmetrical openings or recesses that form a support 192 for the wick structure 19. The support 192 can, for example, serve to hold a carrier 4 and/or the wick structure 19 in the evaporator-tank unit 1. In this example, two recesses are provided, although any number may be provided, in particular 1, 3 to 10 recesses. The recesses have the shape of ring segments and can, for example, also have the shape of slots.

The wick structure 19 with the evaporator 60 according to Figure 6 (c) includes those related to Figure 6 (b) The wick structure 19 is described. The inlet side 61 of the evaporator 60 makes contact with the feed section 184b of the wick structure 19 in a flat 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 fluid reservoir 18 via at least two spaced-apart circumferential sections 180a, 180b, if a bone-shaped wick structure 19 according to Figure 6 (a) is used. Alternatively, the wick structure 19 can fully contact the liquid reservoir 18 in a circumferential section 180a, 180b if an annular wick structure 19 is used according to Figure 6 (b) is used.

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

Figure 7 Figure 1 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), a wick structure 19 with a support 4 (c) and an evaporator-tank unit 1 (d).

The in Figures 7 (a) and 7 (b) The wick structures shown (19) are those relating to Figures 6 (a) and 6 (b) wick structures were explained in 19 from a different perspective.

The wick structure 19 with the carrier 4 according to Figure 7 (c) Figure 1 shows that the carrier 4 is held in the holder 192 of the wick structure 19. The carrier 4 is designed so that it can be inserted into the openings forming the holder 192 and held there in a displacement-resistant manner.

As in Figures 7 (c) and (d) As shown, the carrier 4 can, for example, have electrical contacts 100 that establish an electrical connection to the evaporator 60, so that the evaporator 60 can be electrically contacted and controlled by an external part with respect to the evaporator tank unit 1. Figure 7 (d) shows the evaporator tank unit made of Figure 6 (d) From another perspective. The liquid tank 18 forms the outer part of the vaporizer-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 Figure 1 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 hollow cylindrical with a longitudinal axis and has a radially extending feed section 184b at one end face 195. The hollow cylindrical wick structure 19 has a cavity 196 that can geometrically enclose and/or store liquid 50 in the liquid reservoir 18.

The hollow cylindrical wick structure 19 can, for example, fully contact a cylindrical liquid tank 18 at a circumferential section 180a, 180b corresponding to an inner surface 181 of an outer wall 182 of the liquid storage tank 18. In this embodiment, the wick structure 19 can consist entirely of a porous material. The wick structure 19 can be inserted into a liquid storage tank 18 and ensures that liquid 50 is in contact with the wick structure 19, regardless of its orientation or fill level.

Advantageously, the wick structure 19 forms the liquid reservoir 18. For this purpose, the wick structure 19 can have a liquid-tight outer wall 182, thus forming the outer wall 182 of the liquid reservoir 18. This eliminates the need for a separate component for storing liquid 50, which forms the liquid reservoir 18.

For example, the wick structure 19 can consist of a porous and pressed glass. Thus The pore size and pore distribution can be precisely adjusted. The feed section 184b can have a larger number of pores, each with a smaller volume than the storage section 184a. The storage section 184 can also have a pore size gradient, with the pore size decreasing from the evaporator 60 and/or, for example, the pore size remaining constant in the hollow cylindrical section of the wick structure 19. By, for example, painting and/or coating, the outer wall 182 of the wick structure 19 can be sealed liquid-tight to the outside, thus creating the liquid storage reservoir 18 itself.

Advantageously, the wick structure 19 is colored to, for example, make it possible to recognize the fill level of the liquid reservoir 18 and/or to increase the visual appeal.

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

An air channel 30 is provided coaxially around the longitudinal axis L, which preferably runs concentrically with the outer wall 182 of the liquid storage tank 18.

Claims (13)

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), 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 block-shape 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) is made of a porous glass.
12. Vaporizer tank unit (1) according to any one of the preceding claims, characterized in that

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