ES3027367T3 - Aerosol generation device - Google Patents

Abstract

The invention provides an aerosol generating device configured to operate with a replaceable article (16) comprising a storage compartment, comprising: - a receptacle (10) extending along a receptacle axis (A), defining an inner surface of the receptacle and configured to receive the replaceable article (16); - a heating system configured to heat the replaceable article (16) when it is received in the receptacle (10); the aerosol generating device is characterized in that the inner surface of the receptacle comprises at least one protuberance (14) protruding from the inner surface of the receptacle and configured to compress a portion of the airflow path of the storage compartment to reduce its cross-sectional area, when the replaceable article (16) is received in the receptacle (10); The or each protuberance (14) defines a protuberance surface adjacent to the inner surface of the receptacle and forms an angle with the inner surface of the receptacle greater than 100° along the entire length of the protuberance (14) in an airflow direction. (Automatic translation with Google Translate, no legal value)

Description

DESCRIPTION

Aerosol generating device

TECHNICAL FIELD

The invention relates to an aerosol generating device and an aerosol generating assembly comprising the device and a replaceable article comprising vaporizable material.

PREVIOUS TECHNIQUE

In recent years, aerosol-generating devices, such as e-cigarettes, have become popular as replacements for conventional smoking articles. In these devices, a vaporizable material, such as tobacco, is heated. This can be accomplished, for example, by susceptors embedded in the vaporizable material and heated by one or more coils surrounding a receptacle adapted to accommodate the replaceable article. In other words, susceptors are used in induction heating devices that are heated by eddy currents produced by surrounding coils and induced within the susceptors.

In this context, uniform heat distribution within the vaporizable material is a problem, since, first, cold air is continuously supplied from an air inlet. Second, the temperature is often particularly high immediately around the susceptors, which are typically thin and generally extend in the airflow direction between the air inlet and the air outlet. This also applies to other heating methods, such as those involving heating tracks, cups, and/or blades. In these cases, the vaporizable material does not contain a heating element such as a susceptor, but the thermal gradient described above across the vaporizable material between the inlet and outlet remains essentially the same.

EP 3 610 741 A1 discloses an aerosol generating device, including: a hollow housing comprising a path for accommodating a cigarette, an opening open to the outside at one end of the path such that the cigarette is inserted into the opening from the outside, a through hole connected to the other end of the path and a protrusion projecting from the path to come into contact with a portion of an outer surface of the cigarette; and a heater having a side end portion passing through the through hole and arranged within the path to be inserted into the cigarette accommodated in the path, the heater being configured to heat the cigarette when electricity is applied.

Document WO 2020/074600 A1 discloses an aerosol generating device, having a heating chamber for receiving a substrate carrier containing an aerosol substrate. The heating chamber comprises a first open end, a chamber side wall, and a base at a second end of the chamber side wall opposite the first open end, wherein the base comprises a platform extending from a portion of the base toward the open end from an inner surface of the base.

SUMMARY OF THE INVENTION.

In view of the above, an object underlying the invention is to provide an aerosol generating device and assembly, by means of which the heating of the vaporizable material can be made more uniform.

This is achieved by the aerosol generating device described in claim 1.

This is configured to be operable with a replaceable article, such as a tobacco rod, comprising a storage compartment containing a vaporizable material, such as tobacco, the storage compartment defining an airflow path extending between an air inlet and an air outlet through the vaporizable material. The aerosol generating device comprises a receptacle extending along an axis of the receptacle and defining an internal surface of the receptacle and configured to receive the replaceable article in a space bounded by the internal surface of the receptacle such that the airflow path extends along the axis of the receptacle. In addition, a heating system is provided configured to heat the replaceable article received in the receptacle.

In accordance with the invention, the receptacle inner surface comprises at least one protuberance projecting from the receptacle inner surface and configured to reduce the cross-sectional area of the receptacle to compress a portion of the airflow path of the storage compartment, when the item is received in the receptacle.

The or each protrusion defines a protrusion surface adjacent to the receptacle inner surface that forms an angle with the receptacle inner surface greater than 100 degrees along the entire length of the protrusion in an airflow direction. Otherwise, the or each protrusion defines a protrusion surface adjacent to the receptacle inner surface that forms an angle with the receptacle inner surface greater than 100 degrees along at least an upstream portion of the protrusion in an airflow direction. This will prevent unwanted turbulence and recirculating eddies or vortices downstream of the protrusions, which are disadvantageous since vapor can become trapped in the vortices and condense. The smooth shape also helps maintain good contact between the receptacle and the replaceable article, which is advantageous, for example, when resistive heating is used in the receptacle wall. The preferred angle ranges at the point, as seen in a longitudinal sectional view, where the protuberance emerges from the inner wall, are 100 to 175 degrees, with 130 to 170 degrees being preferred.

The characteristic that the protrusion surface forms an angle with the inner surface of the receptacle that is greater than 100 degrees along the entire length of the protrusion in an airflow direction may mean that the angle value remains greater than 100 degrees along the entire length of the protrusion in the airflow direction. For example, this characteristic may imply that the protrusion surface becomes shallower along the airflow direction compared to the angle at the point where the protrusion emerges from the inner wall, provided that the angle remains greater than 100 degrees along the entire length of the protrusion in the airflow direction.

In particular, the feature that the protuberance surface forms an angle with the receptacle inner surface that is greater than 100 degrees along the entire protuberance in an airflow direction may mean that an angle between a straight line (tangent) at each point of the protuberance profile in a cross-section of the protuberance along the airflow direction and the receptacle inner surface is greater than 100 degrees.

For example, in case the protuberance has an ascending portion, an upper portion and a descending portion, an angle between a straight line at a point near the upper portion of the protuberance and the inner surface of the receptacle may be close to 180 degrees and therefore greater than 100 degrees, because the straight line may be close to parallel to the inner surface of the receptacle in this case, as viewed along the airflow direction. Other aspects related to the feature relating to the angle between the protuberance surface and the inner surface of the receptacle will become apparent from the detailed description of the preferred embodiments and the drawings.

In general, the airflow direction can be understood as the direction from the air inlet to the air outlet in which the air flows during use of the aerosol-generating device. The airflow direction can be parallel to the receptacle axis.

The angle described further provides a "smooth" shape of the protuberance, allowing, for example, the replaceable article to be inserted and removed from the receptacle without damaging it. Furthermore, the effect on which the present invention is based is similar to that of a Venturi tube, since the compression or reduction of the cross-sectional area of the air flow path leads to an acceleration of the air flowing through the replaceable article. This will remove heat, for example, from particularly hot areas and transport heat in the form of hot air to cooler areas. This will make heating more uniform, which is advantageous for efficient use of the vaporizable material. The protuberances furthermore have the advantageous effect of fixing the replaceable article in place. The protuberances may have identical or different dimensions radially and/or axially and/or circumferentially and/or constant or variable heights and may be provided in axially and/or circumferentially offset or staggered positions. Additionally, longitudinal protrusions can be oriented with this extension parallel to the receptacle axis or at an angle to this axis. The maximum number of protrusions is currently expected to be 64. The shape of the protrusions can also be referred to as aerodynamic.

Preferred embodiments are described in the additional claims.

Initial simulations have shown that the desired effect of accelerating the flow while still promoting laminar or transitional flow can be obtained in particular when the or each protuberance has a maximum height measured along an axis perpendicular to the receptacle axis between 2 and 15% of the receptacle diameter, which is in accordance with the invention, with 5 to 10% of this diameter being preferred. In other words, the space available for the replaceable article, such as a tobacco rod, is reduced by the mentioned values, and the available cross-sectional area is restricted. In particular, the cross-sectional area can be reduced by between 1 and 15%, preferably between 2 and 8%. The mentioned values appear particularly suitable for typical receptacle dimensions with a diameter of 7 to 7.5 mm, in particular 7.1 mm, and a length of 37 to 38 mm, in particular 37.5 mm.

It is also currently expected to be advantageous when the maximum length of the or each protuberance measured along the axis of the receptacle is between 5 and 75% of the receptacle length measured along the axis of the receptacle, and preferably between 10 and 65% of this length, with between 15 and 55% being further preferred. More preferred lengths may be around 20% of said receptacle length.

The desired "smooth" shape of the or each protuberance can be obtained particularly when it has an ascending portion, an upper portion and a descending portion.

In this context, the protuberance can typically be symmetrical, both upward and downward, with respect to the upper portion. However, asymmetrical shapes can also be chosen.

Furthermore, an advantageous shape is expected for a rising portion defining transverse dimensions that gradually increase from the receptacle inner surface to the upper portion, and/or the descending portion defining transverse dimensions that gradually decrease from the upper portion to the receptacle inner surface.

In particular, the forms described in claim 7 are expected to show advantageous effects.

Although a single protuberance will already have the desired effect, improved effects will be achieved, when a plurality of protuberances are provided, which are arranged on the inner surface of the receptacle axially and/or circumferentially.

In accordance with the observation that the temperature is particularly high at the air outlet of the storage compartment, it is preferred that the or each protrusion be arranged adjacent to the air outlet.

While the or each protrusion may be provided on the inner surface of the receptacle in a fixed manner, in particular integral with the receptacle wall, at least one protrusion may also be movable along the receptacle axis. Furthermore, the user can place them in place after inserting the article into the receptacle. This will help prevent damage to the replaceable article, particularly to the base of a stick-shaped article, which is inserted into the receptacle with the base facing forward.

Thus, the or each protuberance can also be movable along an axis perpendicular to the axis of the receptacle, in order to achieve the effect described above. In any case, it is sufficient for it to protrude from the internal surface of the receptacle. Typically, the protuberance will constitute portions of the internal surface and will be smoothly connected to it, i.e., avoiding sharp edges and involving radii of curvature.

As indicated above, the invention is particularly useful in connection with an induction heating system, wherein the storage compartment for the replaceable article comprises at least one susceptor. In this context, it is currently preferred that the number of protrusions be equal to the number of susceptors.

Furthermore, heating may be unified, where an upper portion of the or each protuberance is oriented toward the downstream end and/or the hottest part of the corresponding susceptor, when the replaceable article is received in the receptacle.

Alternatively or additionally, the heating system may comprise one or more heating elements extending along at least a portion of the receptacle's inner surface and the contact surface of at least one protrusion.

Finally, the advantages described above can be obtained particularly when the aerosol generating device described herein is combined with a replaceable article, with which the aerosol generating device is adapted to cooperate.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described with reference to exemplary embodiments thereof shown in the drawings, in which

Figure 1 is a cut-away perspective view of a first embodiment;

Figure 2 is a cut-away side view of the first embodiment;

Figure 3 is a cut-away side view of a second embodiment;

Figure 4 is a cut-away side view of a third embodiment;

Figures 5A to 5G are side and plan views of further embodiments of protrusions;

Figure 6 is a cut-away side view of another embodiment with a replaceable article inserted;

Figure 7 is a cut-away side view of another embodiment similar to that of Figure 6;

Figure 8 is a cutaway side view of another embodiment with additional parts of an aerosol generating device shown; and

Figures 9A, 9B are side views of embodiments of protrusions in support of the meaning of the angle between the protrusion surface and the receptacle inner surface.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

As can be seen in Figure 1, a receptacle 10 of an aerosol generating device is essentially tubular in shape and adapted to accommodate a replaceable article, such as a tobacco rod. As indicated by arrow A, air flows substantially through a tobacco rod along the axis of the receptacle, and will enter the receptacle 10 at an air inlet 12 in a substantially cold state. Along the path of the air flow, the tobacco rod includes susceptors adapted to cooperate with one or more induction coils (not shown) around the receptacle to heat itself and transfer the heat to the surrounding tobacco. In the embodiment shown, two protrusions 14 are formed at the same position along the axial direction and at diametrically opposite positions along the circumferential direction. Similar to a Venturi tube, the airflow in the area of the protrusions, where the tobacco rod is correspondingly constricted, is accelerated, so that the hot air can be quickly transported away from the particularly hot area surrounding the susceptors.

As can be seen particularly in Figure 2, the protrusions have a smooth cross-sectional geometry, so that no unwanted turbulence is created, and a tobacco rod can be inserted, sliding between the protrusions without risk of damaging the tobacco rod.

This also applies to the embodiment of Figure 3, which differs from that of Figures 1 and 2 in both the shape and number of protrusions. First, the protrusions have an asymmetric shape, with a more pronounced ascending portion, viewed in the direction of flow, and a less pronounced descending portion. This allows, in particular, easy insertion of a tobacco rod in a direction opposite to the flow direction. Second, unlike Figures 1 and 2, several protrusions, for example 12 protrusions, are provided equidistant along the circumference of the receptacle. Furthermore, the transverse dimensions of the ascending portion increase with a greater gradient, as seen in the direction of flow, than the gradient, whereby these dimensions decrease in the descending portion, as can be seen in the central part of Figure 3, similar to a teardrop shape.

As shown in Figure 4, multiple protrusions may also be provided at different axial positions, which can be considered a staggered arrangement. Furthermore, in the embodiment shown, the protrusions at different axial positions are further offset in the circumferential direction. It goes without saying that multiple protrusions may also be provided at more than two axial positions, and that the distance between the protrusion positions in the circumferential direction may be the same over the entire circumference or may vary. Furthermore, any protrusion arrangement shown in the figures may be chosen with symmetrical protrusions as shown in Figures 1, 2, and 4, as well as asymmetrical protrusions as shown in Figure 3, including any other shapes shown in Figure 5. In this context, when there are multiple protrusions, they may all have the same shape or different shapes.

As can be seen from Figure 5, additional smooth and/or streamlined shapes will be suitable, such as a chevron (A), arrowhead (B), asymmetrical fillet combined with a chamfer as a rising portion (C), symmetrical fillet (D), asymmetrical fillet (E), symmetrical chamfer (F), and asymmetrical chamfer (D). The chevron and arrowhead essentially have a point at one end, and their shape, as seen in a plan view, can be described as essentially triangular. Unlike an arrowhead, which corresponds fairly well to a triangular shape in a plan view, a chevron has a cutout, as seen in a plan view, on the side opposite the point. A chamfer essentially has a flat, sloping surface, as seen in a cross-sectional view, and a fillet is essentially oval or elliptical, as seen in a plan view. The flow direction will normally be from right to left in Figure 5.

As shown in particular in Figures 1 to 4, one or more protrusions may be formed by thickening the receptacle wall. Alternatively, the receptacle wall may have a uniform wall thickness, and the one or more protrusions may be formed as a convex shape within the receptacle corresponding to a concave shape on the outside thereof. As can be seen in particular in Figures 2 to 5, each protrusion has a protrusion surface adjacent to the receptacle inner surface that forms an angle α with the receptacle inner surface greater than 100°, especially in the embodiment of Figures 2, 4 and 5, apart from 5B, this angle is significantly greater than 100° and remains this large along the entire protrusion as viewed in an airflow direction. In other words, each protrusion lacks surfaces that extend "sloping" toward the inner surface of the receptacle, which would create unwanted turbulence.

The measurement and, respectively, the determination of the angle a between the protuberance surface and the inner surface of the receptacle is illustrated in detail in Figures 9A and 9B which illustrate two different configurations of the protuberance 14. In Figure 9A, the protuberance 14 has a roof-like shape with a linear ascending portion (portion comprising point A) and a linear descending portion (portion comprising point B) along the airflow direction (indicated by the arrow). In Figure 9B, the protuberance 14 has a semicircular shape with an ascending portion that gradually becomes shallower (portion comprising point A) and a descending portion that gradually becomes steeper (portion comprising point B) along the airflow direction (indicated by the arrow). Referring to Figures 9A and 9B, the feature that the protuberance surface forms an angle α with the receptacle inner surface that is greater than 100 degrees (100°) along the entire length of the protuberance 14 in an airflow direction means that an angle between a straight line (tangent) at each point of the profile of the protuberance 14 in a cross section of the protuberance along the airflow direction and the receptacle inner surface is greater than 100 degrees.

In Figures 9A and 9B, such a straight line (tangent) is exemplarily shown at points A and B by the dashed lines. In the ascending portions (portions comprising points A), the angle α is measured with respect to the inner surface of the receptacle upstream of the protuberance 14 with respect to the airflow direction. In the descending portions (portions comprising points B), the angle α is measured with respect to the inner surface of the receptacle downstream of the protuberance 14 with respect to the airflow direction. While the angle α remains the same at each point of the protuberance 14 in the ascending portion of Figure 9A, it changes, i.e., becomes larger, when going along the airflow direction in the ascending portion of the protuberance 14 shown in Figure 9B.

Figure 6 shows a receptacle 10 with two diametrically opposed protuberances 14 similar to those in Figure 5D or F. Figure 6 additionally shows a replaceable article 16, such as a tobacco rod, housed in the receptacle 10 and correspondingly compressed in the area of the protuberances 14. This compression firstly brings the tobacco strands 18 closer together in the area of the protuberances 14 and secondly bends the susceptors 20 housed in the replaceable article 16. These susceptors 20 may have a curved, convex shape already in the original state, i.e. without being compressed by the protuberances 14. In particular, the convex shapes of two or more susceptors may be oriented relative to each other towards the center of the replaceable article 16. Alternatively or additionally, the convex shape shown in the figure may be caused by compression in the area of the protuberances14.

In any case, as best illustrated in Figure 7, the cross-sectional area of the replaceable article 16 is smaller in the area of the protrusions 14, so that the flow velocity increases and heat is transported at a greater rate than in the area of the inlet and outlet of the replaceable article shown. While the location of the susceptors, which are typically thin strands of material heatable by a surrounding coil (not shown), may correspond to that of the protrusions 14 and may be substantially symmetrical therewith, as shown in Figure 6, the susceptors may also be offset somewhat toward the inlet 12. In the embodiment shown in Figure 7, the inlet end of each susceptor is somewhat closer to the inlet 12 of the receptacle 10 than is the inlet end of each protrusion 14, and the susceptors cover approximately two-thirds of the longitudinal extent of the protrusions. As mentioned, in the embodiment of Figure 6, the location of the susceptors 20 is symmetrical to that of the protuberance 14, and their input end is somewhat further from the inlet 12 of the receptacle than the input end of the protuberances 14, and their output end is somewhat further from the outlet of the receptacle than the output end of the protuberances 14.

Furthermore, as indicated in Figure 7, due to the asymmetric position of the susceptors, they are closer together towards their output end than at their input end.

The above-described effect of compressing the replaceable article 16 in order to rapidly remove heat from particularly hot areas is also achieved by the embodiment of Figure 8, in which protrusions 14 are provided at the outlet end of the receptacle and are formed as heating elements. In other words, unlike the embodiments described above, the replaceable article 16 is not heated from within, such as by means of the susceptors 20, but from the walls of the receptacle. The principle underlying the invention, i.e., providing protrusions to compress or restrict the airflow path, remains the same. It should also be mentioned that the susceptors could be located in an area corresponding to the protrusions 14 shown in Figure 8, when induction heating is used instead of external heating as in the embodiment of Figure 8. For clarity, Figure 8 also shows, downstream of the outlet end of the receptacle 10, a support 22 with an air passage 24, as well as, downstream of the support 22, a filter 26.

Claims (15)

1. An aerosol generating device configured to operate with a replaceable article (16) comprising a storage compartment containing a vaporizable material, the storage compartment defining an air flow path extending between an air inlet (12) and an air outlet through the vaporizable material; the aerosol generating device comprising: - a receptacle (10) extending along a receptacle axis (A), defining a receptacle inner surface and configured to receive the replaceable article (16) in a space delimited by the receptacle inner surface such that the air flow path extends along the receptacle axis (A); - a heating system configured to heat the replaceable article (16) when it is received in the receptacle (10); the aerosol generating device is characterized in that the receptacle inner surface comprises at least one protuberance (14) protruding from the receptacle inner surface and configured to reduce the cross-sectional area of the receptacle to compress a portion of the airflow path of the storage compartment, when the replaceable article (16) is received in the receptacle (10); the or each protuberance (14) defining a protuberance surface adjacent to the receptacle inner surface and forming an angle with the receptacle inner surface greater than 100° along the entire length of the protuberance (14) in an airflow direction wherein the maximum height of the or each protuberance (14) measured along an axis perpendicular to the receptacle axis (A) is between 2% and 15% of the receptacle diameter. 2. The aerosol generating device according to claim 1, wherein the maximum height of the or each protuberance (14) measured according to an axis perpendicular to the receptacle axis (A) is between 5% and 10% of the receptacle diameter. 3. The aerosol generating device according to claim 1 or 2, wherein the maximum length of the or each protuberance (14) measured according to the receptacle axis (A) is between 5% and 75% of the receptacle length measured according to the receptacle axis (A), and preferably between 10% and 65% of said length. 4. The aerosol generating device according to any one of the preceding claims, wherein the or each protuberance (14) forms an ascending portion, an upper portion and a descending portion; The ascending portion extends from the inner surface of the receptacle to the upper portion and the descending portion extends from the upper portion to the inner surface of the receptacle. 5. The aerosol generating device according to claim 4, wherein the ascending portion is symmetrical to the descending portion with respect to the upper portion. 6. The aerosol generating device according to claim 4 or 5, wherein the ascending portion defines transverse dimensions that gradually increase from the inner surface of the receptacle to the upper portion, and/or the descending portion defines transverse dimensions that gradually decrease from the upper portion to the inner surface of the receptacle. 7. The aerosol generating device according to any one of the preceding claims, wherein the shape of the or each protuberance (14) is selected from the group consisting of: - chevron; - arrowhead; - asymmetrical fillet and chamfer; - symmetrical fillet; - asymmetrical fillet; - symmetrical chamfer; - asymmetrical chamfer. 8. The aerosol generating device according to any one of the preceding claims, comprising a plurality of protuberances (14) arranged on the receptacle inner surface axially according to the receptacle axis (A) and/or circumferentially. 9. The aerosol generating device according to any one of the preceding claims, wherein the or each protrusion (14) is arranged to be adjacent to the air outlet of the storage compartment, when the replaceable article (16) is received in the receptacle (10). 10. The aerosol generating device according to any one of the preceding claims, wherein the or each protuberance (14) is movable according to the receptacle axis (A). 11. The aerosol generating device according to any one of the preceding claims, wherein the or each protuberance (14) is movable along an axis perpendicular to the axis of the receptacle (A) between a coupled position and an uncoupled position; The replaceable article (16) is freely movable within the receptacle (10) along the receptacle axis (A) when the or each protrusion (14) is in the disengaged position and is locked in the receptacle (10) when the or each protrusion (14) is in the engaged position. 12. The aerosol generating device according to any one of the preceding claims, wherein the heating system is an inductive heating system comprising a coil configured to create a magnetic field, the replaceable article storage compartment (16) comprising at least one susceptor (20) extending along the airflow path between an upstream end and a downstream end, and being capable of generating heat when placed in the magnetic field created by the coil; the or each protuberance (14) is arranged to face at least partially toward a susceptor (20) of the replaceable article storage compartment (16), when the replaceable article (16) is received in the receptacle (10); Preferably, the number of protuberances (14) is chosen equal to the number of susceptors (20). 13. The aerosol generating device according to claim 12, wherein the or each protuberance (14) defines an upper portion arranged to face the downstream end of the corresponding susceptor (20), when the replaceable article (16) is received in the receptacle (10). 14. The aerosol generating device according to any one of claims 1 to 11, wherein the heating system comprises one or more heating elements extending along at least a part of the inner surface of the receptacle and the contact surface of the or each protuberance (14). 15. An aerosol generating assembly comprising: - a replaceable article (16) comprising a storage compartment containing a vaporizable material, the storage compartment defining an air flow path extending between an air inlet (12) and an air outlet through the vaporizable material; - an aerosol generating device according to any one of the preceding claims, configured to operate with the replaceable article (16).