EP4349131A1

EP4349131A1 - Vaporization device for an inhaler

Info

Publication number: EP4349131A1
Application number: EP22732932.3A
Authority: EP
Inventors: Eiko Bäumker; Thomas Bilger; Muhannad Ghanam; Timo GERACH; Uwe Pelz; Mohamad Reza SABERI; Peter Woias; Luca CONRAD; Frank GOLDSCHMIDTBÖING
Original assignee: Koerber Technologies GmbH
Current assignee: Koerber Technologies GmbH
Priority date: 2021-06-02
Filing date: 2022-05-30
Publication date: 2024-04-10
Also published as: US20240251481A1; DE102021114281A1; WO2022253734A1

Abstract

The invention relates to a vaporization device (20) for an inhaler, comprising an electrical resistance heating body (23) for vaporizing liquid (33), which has been brought into contact with the resistance heating body (23), by means of electrical energy. The resistance heating body (23) consists of a material, in which, in a temperature range around a vaporization temperature, the change in resistance per temperature interval is at least three times as great as in a temperature range around room temperature.

Description

WO 2022/253734 gschinenbau GmbH ^H PCT/EP2022/064548

Vaporization device for an inhaler

The present invention relates to a vaporization device for an inhaler, comprising an electrical resistance heating element for vaporizing liquid brought into contact with the resistance heating element by means of electrical energy.

Such an inhaler is known, for example, from DE 10 2017 123 868 B4, DE 10 2017 123 869 B4 and DE 10 2017 123 870 B4.

The control of the electrical heating power or the heating temperature

15 of an evaporator in the form of a resistance heating element is desirable in order to achieve a constant or adjustable amount of steam and to prevent the increased formation of pollutants at elevated temperatures. Various methods of radiator control are known, see for example DE 10

20 2019 113 645 B4. Essentially, these can be divided into methods for temperature control and for power control. The processes are subject to specific challenges when the initial temperature of the radiator or the liquid varies greatly.

Based on the prior art, the invention is based on the object of providing a device and a method for an inhaler which, despite the resistance of the heating element subject to tolerances, enables the heating element temperature to be determined with a tolerance which is significantly lower than the tolerance at the beginning

30 temperatures is. WO 2022/253734 gschinenbau GmbH ^H PCT/EP2022/064548

The invention solves this problem with the features of the inde pendent claims. According to the invention, the resistance heater consists of a material in which, in a temperature range around an evaporation temperature, the change in resistance per

5 temperature interval is at least three times larger than in a temperature range around room temperature. A temperature range around an evaporation temperature is a temperature range that includes at least one average evaporation temperature (for example 250°C) and the lower limit of which is above 100°C.

10 A temperature range around room temperature is a temperature range that includes room temperature (25 °C) and has an upper limit below 100 °C.

To clarify the underlying problem

15 Next three cases are considered: a normal case with a radiator and liquid temperature of, for example, T ₀ = 25 °C (room temperature), a low temperature case with, for example, T ₀ = -20 °C (e.g. outside temperature in extreme winter) and a high temperature case with e.g. T ₀ = 50 °C (e.g. Inhala

20 tor lay in the sun). A temperature sensor for measuring the heating element temperature is advantageously not provided, since the sensor and the electrical contacts for evaluating the sensor would make the vaporization device much more expensive. The only thing available for measuring the temperature is the electrical resistance of the

25 radiators at your disposal. The increase in temperature is calculated from the relative increase in resistance compared to the initial resistance or from the absolute resistance of the radiator.

30 With heaters made of p-doped silicon, the relative change in resistance per temperature is approx. 0.2%/K, the basic resistance WO 2022/253734 gschinenbau GmbH ^H PCT/EP2022/064548 of a radiator is approx unacceptable.

5 When using the relative resistance change related to the initial resistance, a tolerance window of only 7.7 K would result. Accordingly, a relative method for temperature measurement is advantageously used. The temperature value is thus advantageously derived from the current resistance R _ak t and the resistance Ro to Be

10 calculated from the start of the heating process. However, this leads to a problem if the initial temperature To is not known, since this uncertainty (70 K in the example given) also affects the measurement result.

15 In the case of capacity regulation or capacity control, possibly with shutdown at excessively high temperatures to avoid excessive pollutant formation, the same problem arises in principle. Switching off when the temperature is too high can only follow if the temperature is determined with sufficient accuracy

20 can. The amount of steam generated also depends on the ambient temperature. At low temperatures (e.g. -20°C) more energy is required to heat the liquid up to the evaporation point, and the heat losses to the environment are also higher. Overall it turns out at the same

25 heating power thus a significantly lower amount of steam than at ho hen initial temperatures (for example 50 ° C).

According to the invention, a heating element is now used that is within the tolerance range of the initial temperature (here, for example, -20°C to

30 + 50°C) shows a comparatively small change in resistance and in the range of the evaporation temperature (here for example WO 2022/253734 gschinenbau GmbH ^H PCT/EP2022/064548

200°C to 300°C) has a comparatively high change in resistance with temperature. More specifically, in a temperature range around an evaporation temperature, the change in resistance per temperature interval is at least three times as large, preferably

5 at least five times as large, more preferably at least seven times as large as in a temperature range around room temperature. In this way, the initial resistance Ro of the heater is essentially temperature-independent, or at least considerably less temperature-dependent, so that the tolerance of the initial tem

10 temperature has only a small or very small influence on the measured temperature in the area of the evaporation temperature.

A corresponding resistance characteristic can be achieved by using a material with a suitable temperature for the heating element

15 dependence of the resistivity is used. Such a material is boron-doped silicon, for example with a dopant concentration in the range of 4-10 ¹⁸ /cm ³ . In this range, boron-doped silicon shows an almost constant specific resistance in the range from -20°C to +50°C, for example, and in

20 measuring range (here, for example, greater than 200° C.) has a considerably greater and advantageously even largely linear temperature dependency. A linear temperature dependency of the material in the range of the evaporation or operating temperature simplifies the determination of the temperature and is therefore preferred. Generally, a monoto

25 ne temperature dependency sufficient so that a temperature can be clearly assigned to each resistance value; a strictly linear temperature dependency is therefore not absolutely necessary.

30 It is conceivable that a suitable temperature dependence of the specific resistance can be achieved with other doped semiconductors, e.g. WO 2022/253734 gschinenbau GmbH ^H PCT/EP2022/064548 se thallium doping or arsenic doping of a semiconductor such as silicon.

The doping is preferably at least 10 ¹⁶ /cm ³ , preferably at least 10 ¹⁷ 7cm ³ , more preferably at least

10 ¹⁸ /cm ³ . A sufficient and suitable doping level is important for achieving the desired temperature dependence of the specific resistance of the heater. The doping generally depends on the semiconductor material and on the doping material 10 (foreign atoms).

In a temperature range around an evaporation temperature, the relative change in resistance of the heating element material per temperature interval is preferably at least 10% per 100 K. 15 In a temperature range around room temperature, the relative change in resistance of the heating element material per temperature interval is preferably at most 3.5% per 100 K.

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

Fig. 1 is a schematic view of an electronic inhala gate;

25

Fig. 2 is a perspective view of a vaporization device for an inhaler;

3 shows a temperature characteristic of a heating element made of a material according to the invention; WO 2022/253734 gschinenbau GmbH ^H PCT/EP2022/064548

4 theoretical temperature dependencies of the specifi's resistance of two materials in comparison;

5 shows a measurement curve of the resistance of a heating element 5 made of boron-doped silicon together with theoretically calculated values; and

6 shows a table with columns for initial temperature, temperature when 1.28 times the initial resistance io is reached and resistance at the initial temperature.

The electronic inhaler 10, here an electronic cigarette product, comprises a housing 11 in which an air duct 30 is provided between at least one air inlet opening 31 and an air outlet opening 15 at a mouth end 32 of the cigarette product 10. The mouth end 32 of the cigarette product 10 denotes the end at which the consumer pulls for the purpose of inhalation and thereby applies a negative pressure to the cigarette product 10 and generates an air flow 34 in the air duct 30 .

20

The inhaler 10 comprises a vaporization device 20 and a liquid reservoir 18, which can be part of an exchangeable vaporizer cartridge 17, for example. The air sucked in through the inlet opening 31 is guided in the air duct 30 as an air flow 25 to, through, or along the evaporation device 20 . The evaporation device 20 is connected or connectable to the liquid storage device 18 in which at least one liquid 33 is stored. The vaporization device 20 vaporizes liquid 33 which is supplied to it from the liquid reservoir 18 30 and releases the vaporized liquid as an aerosol/

Vapor at an outlet side 26 of the vaporization device 20 in WO 2022/253734 gschinenbau GmbH ^H PCT/EP2022/064548 the air flow 34 to. The liquid 33 to be metered that is stored in the liquid reservoir 18 is, for example, a mixture comprising one or more of the following components in any combination: 1,2-propylene glycol, glycerol, water, at least

5 tens a flavor. The liquid can contain at least one active substance, for example nicotine.

The electronic cigarette 10 also includes an electrical energy store 14 and an electronic control system

10 direction 15, which can be arranged in a base part 16 of the inhaler 10, for example. The energy store 14 can in particular be an electrochemical disposable battery or a rechargeable electrochemical battery, for example a lithium-ion battery. In the example shown in Figure 1, the energy storage

15 cher 14 in a part of the inhaler 10 facing away from the mouth end 32 . The evaporator cartridge 17 is advantageously arranged between the energy store 14 and the end 32 of the mouth. The electronic control device 15 is advantageously digital and preferably includes a microprocessor and/or microcontroller

20 people

A sensor 13, for example a pressure sensor or a pressure or flow switch, is advantageously arranged in the housing 11, the control device 15 being based on one of

25 the sensor 13 output sensor signal can determine that a consumer pulls on the mouth end 32 of the inhaler 10 to inhale. In this case, the control device 15 controls the evaporation device 20 in order to supply liquid 33 from the liquid storage device 18 as an aerosol/vapor into the air flow 34

30 ben. WO 2022/253734 gschinenbau GmbH ^H PCT/EP2022/064548

The evaporation device 20 comprises at least one evaporator in the form of a resistance heater 23 (see FIG. 2) and advantageously a capillary element 12 for supplying liquid 33 from the liquid reservoir 18 to the heater 23. In Be

In the operating state of the inhaler 10, the heating element 23 is electrically connected to a heating voltage source 22, which can be controlled by the electronic control device 15, via electrical lines 25. The heating voltage source 22 is preferably via the electric 29 on opposite sides of the radiator 23 with the

10 sem connected, so that one of the heating voltage source 22 he testified electrical heating voltage Uh leads to a current flow through the heater 23. The heating voltage source 22 draws electrical energy from the electrical energy store 14. Due to the ohmic resistance of the electrically conductive heating element 23

15, the current flow leads to a heating of the heating element 23 and therefore to an evaporation of liquid contained in the microchannels 27. The heating element 23 thus acts as an evaporator. Vapor/aerosol generated in this way escapes from the microchannels 27 on the outlet side 26 and is mixed with the air flow 34,

20 see Figure 1. More precisely, when an air flow 34 caused by the consumer pulling through the air duct 30 is detected, the control device 15 activates the heating voltage source 22, whereby the liquid in the micro-channels 27 in the form of vapour/aerosol is released from the micro-channels by spontaneous heating

25 27 driven.

The inhaler 10 advantageously comprises a digital data memory 35 for storing information or parameters relating to the evaporator cartridge 17 . The data memory 35 can be part of the elec

30 electronic control device 15 or connected to it. In the data memory 35 is advantageously information on the WO 2022/253734 gschinenbau GmbH ^H PCT/EP2022/064548 sa composition of the liquid stored in the liquid reservoir 18, information on the process profile, in particular power/temperature control; Data for status monitoring or system testing, for example leak testing; data regarding

5 protection against copying and counterfeiting, an ID for unique identification of the evaporator cartridge 17, serial number, manufacturing date and/or expiration date, and/or number of puffs (number of inhalations puffs by the consumer) or the usage time ge stores.

10

The heating element 23 is provided with a plurality of micro-channels 27 which connect an inlet side 28 of the heating element 23 to an outlet side 26 in a fluid-conducting manner. The inlet side 28 is liquid-conducting via a capillary element 12 with the liquid

15 capacity memory 18 connected. The capillary element 12 is used for passive ven promotion of liquid 33 to be evaporated from a liquid reservoir 18 to the radiator 23 by means of capillary forces. The capillary element 12 is advantageously made of a non-conductive material to prevent unwanted heating of liquid

20 to avoid in the capillary element 12 by current flow.

The average diameter of the microchannels 27 is preferably in the range between 5 μm and 200 μm, more preferably in the range between 30 μm and 118 μm, even more preferably in the range

25 between 18 pm and 100 pm. Because of these dimensions, a capillary effect is advantageously generated, so that liquid penetrating into a microchannel 27 on the inlet side 28 rises through the microchannel 27 until the microchannel 27 is filled with liquid speed. The volume ratio of microchannels 27 to heater

30 body 23, which can be referred to as the porosity of the heating element 23, is for example in the range between 10% and 18%, pre- WO 2022/253734 gschinenbau GmbH ^H PCT/EP2022/064548 partially in the range between 15% and 40%, even more advantageously in the range between 20% and 30%, and is for example 25%. The thickness of the heater 23 and thus the length of the microchannels 27 is preferably in the range between 0.05 mm and 1 mm, white

5 ter 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.

The heating element 23 is preferably block-shaped, for example

10 is parallelepipedal, and preferably monolithic, i.e. the heating element 23 advantageously has no macroscopic cavities apart from the microchannels 27. The heater 23 can therefore be referred to as a block, bulk or volume heater.

The evaporation temperature is preferably in the range between 100°C and 400°C, more preferably between 150°C and 318°C, even more preferably between 190°C and 240°C.

The vaporization device 20 has an electronic measurement

20 circuit 19 for determining the temperature of the heater 23 by measuring the electrical resistance of the heater 23 on. Circuits for measuring the electrical resistance of a current-carrying heater are known per se.

25 A material is used for the heating element 23 that shows a comparatively small change in resistance with the temperature in the tolerance range of the initial temperature, here for example -20 °C to +50 °C, and in the range of the evaporation temperature, here for example 200 °C to 300 °C, a comparatively high resistance

30 level change with temperature. WO 2022/253734 gschinenbau GmbH ^H PCT/EP2022/064548

FIG. 3 shows an example of such a temperature characteristic of a heater 23 according to the invention

5 Basis of calculation. The solid line 41 at low temperatures reflects a measurement in a climatic chamber. The solid line 42 at higher temperatures is a Mes solution with an infrared camera with resistance heating of the heater body 23 again. In the range of the initial temperature between

10 -20 °C and +50 °C the resistance of the heating element 23 only changes by about 20 mΩ (1.01±0.01 W). In the range of the evaporation temperature, here between 150° C. and 250° C., the resistance of the heating element 23 changes significantly by about 210 mΩ (1.14-1.35 W). The resistance change per temperature interval in a

In this example, the temperature range around an evaporation temperature based on the change in resistance per temperature interval in a temperature range around room temperature is (210 mΩ/100 °C)/(20 mΩ/70 °C) = 7.35. In this way, the initial resistance R ₀ of the heater 23 is substantially tempera

20 ture-independent, or at least considerably less temperature-dependent, so that the tolerance of the initial temperature has only a small or very small influence on the measured temperature in the area of the evaporation temperature.

25 A corresponding resistance characteristic can be achieved by using a material with a suitable temperature dependence of the specific resistance for the heating element 23 . The heating element 23 advantageously consists of an electrically conductive, doped semiconductor material, preferably doped silicon. in egg

In a particularly preferred embodiment, the material of the heating element is boron-doped silicon. The boron doping level is WO 2022/253734 gschinenbau GmbH ^H PCT/EP2022/064548 for example in the range between 10 ¹⁸ /cm ³ and 10 ¹⁹ /cm ³ and is for example 4-10 ¹⁸ /cm ³ .

FIG. 4 shows the theoretical temperature dependencies of the specific resistance of boron-doped silicon 43 in comparison to phosphorus-doped silicon 44. Applied here is the specific resistance p in W-cm over the temperature of the radiator pers 23 in °C. The boron-doped silicon (points 43) shows an almost constant specific resistance in the range from -20 °C to +50 °C and in the measuring range (here greater than 200 °C) a largely linear temperature dependency. Phosphorus-doped silicon (item 44), on the other hand, is not suitable because the specific resistance varies greatly in the range from -20 °C to +50 °C.

15 FIG. 5 shows a measured curve of the resistance of a heating element 23 made of boron-doped silicon (solid line) together with the value calculated from the theoretical course (points) of the specific resistance. Both curves are close together and follow a very similar course.

20

The table in FIG. 6 shows the temperature T _max for nine values of the initial temperature To in the range -20° C. to +50° C. when 1.28 times the initial resistance is reached and the initial resistance Ro in ohms. From the table it can be seen that for the curve shown in FIG. 3 there is a tolerance of only approx. 9 K for the temperature determination with the tolerance of the initial temperature of 70 K.

Claims

WO 2022/253734 gschinenbau GmbH HPCT/EP2022/064548 Claims:

Claims 1. Vaporization device (20) for an inhaler, comprising an electrical resistance heater (23) for vaporization

5 fen of the resistance heating element (23) brought into contact with liquid (33) by means of electrical energy, characterized in that the resistance heating element (23) consists of a material in which the change in resistance in a temperature range around an evaporation temperature Per

10 temperature interval is at least three times as large as in a temperature range around room temperature.

2. Evaporation device according to claim 1, characterized in that the material of the resistance heater

15 (23) in a temperature range around an evaporation temperature, the change in resistance per temperature interval is at least five times, preferably at least seven times, greater than in a temperature range around room temperature.

20 3. Evaporation device according to one of the preceding claims, characterized in that the material of the resistance heating element (23) has a monotonic change in resistance with the temperature in a range around an evaporation temperature.

25

4. Evaporation device according to one of the preceding claims, characterized in that the material of the Wi resistance heater (23) in a range around a United evaporation temperature an approximately linear resistance

5. Evaporation device according to one of the preceding claims, characterized in that the material of the Wi resistance heater (23) is a doped semiconductor material, in particular doped silicon.

5

6. Evaporation device according to claim 5, characterized in that the semiconductor material has a boron doping.

10 7. Evaporation device according to claim 5 or 6, characterized in that the semiconductor material has a thallium doping and / or an arsenic doping.

8. Evaporation device according to one of claims 5 to 7,

15, characterized in that the doping of the heating element (23) is at least 10 ¹⁶ /cm ³ , preferably at least 10 ¹⁷ /cm ³ , more preferably at least 10 ¹⁸ /cm ³ .

9. Evaporation device according to one of the preceding

20 claims, characterized in that in a temperature range around an evaporation temperature, the relative change in resistance of the heating element (23) per temperature interval is at least 10% per 100 K.

25 10. Evaporation device according to one of the preceding claims, characterized in that in a temperature range around room temperature, the relative change in resistance of the heating element (23) per temperature interval is at most 3.5% per 100 K.

30