Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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A liquid substance storing container for an aerosol generating device
Field of the invention
The present invention relates to a liquid substance storing container for
an aerosol generating device.
It also concerns an aerosol generating device comprising such a liquid
substance storing container.
Background of the invention
Aerosol generating devices, also commonly called vaporizers or
electronic cigarettes, allow vaporization of a substance to create an aerosol
or mist
that a user inhales.
An aerosol generating device comprises a heat source that heats the
substance, generally a liquid often called e-liquid or e-juice, to create the
aerosol in
a vaporization zone of the aerosol generating device. Channels are also
provided
for routing the aerosol from the vaporization zone to a mouth piece for the
user.
The aerosol generating device often comprises a reservoir configured for
storing the substance in liquid form, and feeders configured for moving the
substance from the reservoir, such as by wicking or capillary action, to a
vaporization
zone for heating or vaporization.
This type of configuration needs to provide sealing means to seal a liquid
outlet hole on the reservoir.
In order to avoid the drawbacks of a reservoir, such as liquid leakages,
US 2018/0289909 discloses a vaporizer adapted to vaporize oil that is stored
in one
or several tabs.
The tab, such as a tablet, cylinder, or disk, can include a porous body for
storing liquid substance. For example, the tab can include a piece of porous
ceramic
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or sintered metal soaked, injected or infused with oil, such as to the point
that the oil
is held in place by capillary action.
In such an embodiment, the vaporizer can include a reservoir configured
for holding one or more tabs and for supporting the tabs during heating.
Such a tab provides a medium for storing, transporting and allowing
vaporization of a substance.
However, the quantity of oil or liquid substance stored in the tab is limited,
and depends on the porosity of the tab. Thus, the packing efficiency, that is
the ratio
between the vaporizable substance volume stored in the storage medium and the
volume occupied by the storage medium (or overall volume), is rather low, and
limited by the volume of the vaporizable substance which can be stored in the
pores
of the porous body of the tab.
The present invention aims to improve the packing efficiency of a liquid
substance storing container for an aerosol generating device.
Summary of the invention
The present invention thus relates to a liquid substance storing container
for an aerosol generating device, comprising a porous body for storing liquid
substance.
According to the invention, the porous body includes a closed internal
cavity surrounded by wall of the porous body, said closed internal cavity
further
storing liquid substance by forming a closed pocket.
Thus, the volume of stored liquid substance in the storing container may
be increased compared to a storing container made of the same porous body,
without a closed internal cavity.
Indeed, the volume of stored liquid substance is not limited to the volume
of the liquid substance which can be stored in the pores of the porous body of
the
tab, but also comprise the volume of the liquid substance stored in the closed
internal
cavity.
The packing efficiency is thus improved compared to a storing container
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made of a homogenous porous body with no internal cavity.
Such a liquid substance storing container allows a significant
optimization of the volume of stored liquid substance, thanks to the closed
internal
cavity which provides the storing container with an internal reservoir of
liquid
substance.
According to one embodiment, the porous body is adapted to absorb a
volume of liquid substance and to retain said volume of liquid substance until
vaporized.
The liquid substance is then absorbed by capillary action in the porous
body and goes through the porous body up to the closed internal cavity in
order to
be stored therein. The volume of liquid substance is then retained both in the
closed
internal cavity and the walls of the porous body surrounding the closed
internal
cavity.
In practice, the porous body has an open-cell structure.
According to one embodiment, the open-cell structure of the porous body
is adapted to retain the liquid substance in the closed internal cavity in a
leak-proof
manner when said porous body is maintained below a threshold temperature of
50 C.
Thus, the storing container is well adapted to store a liquid substance
before its heating and vaporization. The storing container may be manipulated
by a
user without risk of leakage, before using in an aerosol generating device.
Advantageously, the open-cell structure of the porous body is adapted to
release the liquid substance from the closed internal cavity into the porous
body by
capillary action when said porous body is heated at or above said threshold
temperature.
As a consequence, the liquid substance stored in the closed internal
cavity goes gradually into the porous body.
In practice, the open-cell structure of the porous body is adapted to
release, through an outer surface of said porous body, a vaporized liquid
substance
when said porous body is heated at or above said threshold temperature.
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In one embodiment, the pore size of the open-cell structure of said
porous body ranges between 0.5 to 100 micrometers.
As an example, the porous body is made of porous ceramic, sintered
metal, sintered glass or alumina.
In one configuration, the porous body takes the shape of a disk, a
cylinder, a hexagonal prism, or sphere.
In another configuration, the porous body takes the shape of a hollow
cylinder or a hollow truncated cone.
The hollow form of the porous body may facilitate the handling of the
storing container and/or the cooperation of the storing container with a
heating unit
in the aerosol generating device.
In one embodiment, the closed internal cavity has a three-dimensional
shape homothetic to the shape of said porous body.
Preferably, the three-dimensional shape of the closed internal cavity is
concentric with the shape of said porous body.
The closed internal cavity is thus centred in the porous body. The liquid
substance stored in the closed internal cavity can go homogeneously, through
all
the walls of the porous body surrounding the closed internal cavity.
According to another aspect, the present invention relates to an aerosol
generating device comprising a liquid substance storing container as recited
above,
and a heater adapted to heat the porous body at or above a threshold
temperature
of 50 C.
The aerosol generating device present the same advantages as the ones
described in relation with the liquid substance storing container.
In one embodiment, the heater is adapted to heat an outer surface of
said porous body.
In another embodiment, the porous body has a hollow shape and the
heater is adapted to heat an inner surface of the hollow porous body.
Such a heating through an inner surface of the hollow porous body may
improve the transfer of heat to the storing container, in order to speed up
the
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temperature rise in the porous body, and thus the vaporization of the liquid
substance.
Brief description of the drawings
5 Other particularities and advantages of the invention will also
emerge
from the following description.
In the accompanying drawings, given by way of non-limiting examples:
- Figure 1A represents, in a schematic three dimensional view, a liquid
substance storing container according to a first embodiment of the invention;
- Figure 1B represents, in a schematic sectional view, the liquid
substance storing container of Figure 1A;
- Figure 2 represents, in a schematic three dimensional view, a liquid
substance storing container according to a second embodiment of the invention;
- Figure 3 represents, in a schematic sectional view, a liquid substance
storing container according to a third embodiment of the invention;
- Figure 4A represents, in a perspective view, a liquid substance storing
container according to a fourth embodiment of the invention;
- Figure 4B represents, in a schematic sectional view, the liquid
substance storing container of Figure 4A; and
- Figure 5 is a schematic view of an aerosol generating device according
to one embodiment of the invention.
Detailed Description
Figures 1A and 1B depict a liquid substance storing container according
to a first embodiment.
It should be noted that liquid substance storing container is a consumable
item, configured to be used with an aerosol generating device, such as an
electronic
cigarette (e-cigarette). Once the liquid substance initially retained in the
storing
container has been aerolized and thus consumed, the storing container may be
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replaced by another liquid substance storing container. The old storing
container can
be discarded, preferably for recycling.
In the following, the liquid substance encompasses any types of
vaporizable substances including oil, water, ..., which may be vaporized to
form a
mist capable of being inhaled by a user.
As an example, the liquid substance may be a e-liquid well known for
using in the e-cigarettes. Extracts from the cannabis plant can also take the
form of
an oil or oil-like substance.
The liquid substance storing container 10 comprises a porous body 11
for storing the liquid substance.
The porous body 11 may be made of porous ceramic, sintered metal,
sintered glass, alumina or silicon carbide.
The porous body 11 has an open-cell structure, with a matrix of pores
adapted to absorb and then to retain, by capillary action, the liquid
substance until
vaporized.
The pore size of the open-cell structure of the porous body 11 ranges
between 0.5 to 100 micrometers.
As an example, the pore size of the porous body may be equal to 15
micrometers, with the ability to retain 0,5 micrometers particle.
Thanks to its porosity, the porous body 11 may absorb a volume of liquid
substance, for example by infusing: the porous body is immersed in a liquid
bath and
the liquid is sucked into the pores of the porous body 11 by capillary action.
As depicted in Figure 1A, the porous body 11 includes a closed internal
cavity 12.
The closed internal cavity 12 is thus a recess or a chamber surrounded
by the walls 11a of the porous body 11.
The closed internal cavity 12 thus forms a closed pocket or reservoir in
the porous body itself, for storing liquid substance.
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When the porous body 11 is loaded with the liquid substance, the liquid
substance fills both the pores of the porous body 11 and the closed internal
cavity
12.
Thus, the volume of the liquid substance stored in the liquid substance
storing container 10 is increased, and is not limited to the volume of liquid
substance
retained in the pores of the porous body 11.
Taking the overall volume ye occupied by the porous body 11 and the
internal volume Vc of the closed internal cavity 12, the volume Vs of the
liquid
substance stored in the liquid substance storing container 10 is:
Vs = (Ve ¨ Vc) x ep + Vc
wherein ep is the packing efficiency of the porous material of the porous
body 11.
The packing efficiency of a porous material is the ratio, inferior to 1,
between the liquid substance volume which can be stored in the pores of a
storage
medium made in the porous material and the volume occupied by the storage
medium.
Thanks to the closed internal cavity 12, the volume of the stored liquid
substance may be increased compared to the volume (Ve x ep) which would be
stored in a porous body 11 of the same shape, without a closed internal
cavity.
Thus, the number of puffs per liquid substance storing container 10 is
also increased when the liquid substance storing container 10 is used in a
vaporizer.
The liquid substance may be loaded in the closed internal cavity 12 and
the porous body 11 by infusing: the liquid substance storing container 10 can
be
heated, for example at 60 C about, and immersed in a liquid substance bath.
The
liquid substance is sucked into the pores of the porous body 11 by capillary
action
and also into the closed internal cavity 12, though the walls of the porous
body 11.
Alternatively, or in addition, means of pressure may be used in order to
load the liquid substance into the closed internal cavity 12 and the porous
body 11.
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In this first embodiment, the porous body 11 takes the shape of a disk or
a cylinder, with a height H and a cross-sectional surface S. The volume Ve
occupied
by the porous body 11 or the volume envelope is:
ye = H x S.
As illustrated in Figures 1A and 1B, the closed internal cavity 12 has a
three-dimensional shape homothetic to the shape of the porous body 11.
Here, the closed internal cavity 12 takes also the shape of a disk or a
cylinder, with a height H1 and a cross-sectional surface Si. The volume Vc of
the
closed internal cavity 12 is:
Vc = H1 x S1.
Depending on the volume Vc of the closed internal cavity 12, the packing
efficiency of the liquid substance storing container 10 may be more or less
increased.
Preferably, the three-dimensional shape of the closed internal cavity 12
is concentric with the shape of the porous body 12.
In this first embodiment, the cylindrical shape of the closed internal cavity
12 has the same central longitudinal axis X as the one of the cylindrical
shape of the
porous body 11, and the centres of the cylindrical shapes of the closed
internal cavity
12 and the porous body 11 are merged.
The thickness of the walls lla of the porous body 11 surrounding the
closed internal cavity 12 is thus identical in any directions around the
closed internal
cavity 12.
In the first embodiment, the thicknesses t of the top, bottom and side
walls 11a of the porous body 11 are the same.
Of course, the shapes of the porous body and the closed internal cavity
are not limitative.
In particular, the closed internal cavity 12 may also be non-homothetic to
the shape of the porous body 11 and/or be non-concentric with the shape of the
porous body 11.
As depicted in Figure 2, in a second embodiment, the porous body 21 of
the liquid substance storing container 20 may also take the shape of a
hexagonal
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prism, the closed internal cavity 22 taking a same homothetic shape of a
hexagonal
prism or another shape.
In a third embodiment of a liquid substance storing container 30 as
depicted in Figure 3, the porous body 31 may also take the shape of a sphere
or a
ball, the closed internal cavity 32 taking also the shape of a sphere, for
example
concentrically disposed in the porous body 31.
In a fourth embodiment as depicted in figures 4A and 4B, the porous
body 41 of a liquid substance storing container 40 takes the shape of a
truncated
cone, with a longitudinal axis Y. The closed internal cavity 42 has also the
shape of
truncated cone, disposed along the same longitudinal axis Y as the one of the
porous
body 41.
In this fourth embodiment, the porous body 41 is hollow. In this
embodiment, the hollow truncated cone has a hole 45 which extends along the
longitudinal axis Y of the porous body 41.
The hole 45 takes in this embodiment a frusto-conical shape, centrally
disposed in the porous body 41.
Of course, this fourth embodiment with a hollow porous body 41 is not
!imitative. For example, the hollow porous body may take the shape of a hollow
cylinder, with a cylindrical hole. The closed internal cavity takes also the
shape of a
hollow cylinder.
The hole 45 of the porous body 41 is configured to fit with a heating
element of an aerosol generating device.
The liquid substance storing container 10, 20, 30, 40 as described here
above forms a solid consumable comprising a porous body 11, 21, 31, 41
configured
to retain the liquid substrate at an ambient temperature and to release and
vaporize
the liquid substrate when heated to form an aerosol.
Thus, the porous body 11, 21, 31, 41 resists egress or leakage of liquid
substrate through the pores of the porous material absent heating and
vaporization
of the liquid substrate.
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Thus, the porous body 11, 21, 31, 41 also retain the liquid substance in
the closed internal cavity 12, 22, 32, 42 in a leak-proof manner when the
porous
body is maintained below a threshold temperature, and is not heated.
The threshold temperature is set for instance to 50 C, so that the liquid
5
substance storing container 10, 20, 30, 40 may be stored and transported
without
liquid leakage before use, by keeping the liquid substance storing container
10, 20,
30, 40 at room or ambient temperature.
On the contrary, when the porous body 11, 21, 31, 41 is heated at or
above the threshold temperature, the open-cell structure of the porous body
11, 21,
10 31,
41 is adapted to release, through its outer surface, a vaporized liquid
substance.
More precisely, the liquid substance heated in the pores of the porous
body 11, 21, 31, 41, and mainly in the pores of the walls 11a, 21a, 31a, 41a
of the
porous body 11, 21, 31, 41, is vaporized and released from the porous body 11,
21,
31, 41.
Thus the liquid substance exudes through the porous walls 11a, 21a,
31a, 41a only when the porous body 11, 21, 31, 41 is heated via an external
heater,
above the threshold temperature.
The liquid substance is gradually released from the closed internal cavity
12, 22, 32,42 into the porous body 11,21, 31,41, by capillary action, when the
liquid
substance retained in the pores of the porous body 11, 21, 31, 41 is
vaporized.
The closed internal cavity 12, 22, 32, 42 ensures the replenishment of
liquid substance in the pores of the porous body from the closed internal
cavity 12,
22, 32, 42. The closed internal cavity 12, 22, 32, 42 acts as a reservoir for
fulfilling
the pores of the porous material 11, 21, 31, 41.
The heating of the liquid substance in the pores of the porous body 11,
21, 31, 41 may be obtained in a continuous manner, with the gradual
replenishment
of the pores of the porous body 11, 21, 31, 41.
Of course, the examples given here below of a liquid substance storing
container 10, 20, 30, 40 are not limitative.
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For instance, the internal walls of the closed internal cavity 12 may be
provided with ridges or grooves in order to increase the internal area of the
closed
internal cavity 12 in contact with the porous body 12. The transfer of the
liquid
substance from the closed internal cavity 12 into the porous body 11 is thus
increased, ensuring a fast replenishment by capillary action of the pores of
the
porous body 12.
By way of example, an aerosol generating device 50 which could be used
for heating a liquid substance storing container 10, 20, 30, 40 is depicted in
Figure
5 according to one embodiment of the invention.
The aerosol generating device 50 may comprise as usual a housing 51
with a mouth piece 52 at one end for inhalation of the vapour or a mist by a
user.
The aerosol generating device 50 also comprise a heater 53 adapted to
heat a liquid substance storing container 10, 20, 30, 40.
As described here above, the heater is adapted to heat the porous body
of the liquid substance storing container 10, 20, 30, 40 at or above the
threshold
temperature, here set at 50 C.
In this non limitative embodiment, the liquid substance storing container
10, 20, 30, 40 is disposed in a vaporization chamber 54, and the heater 53 is
adapted
to heat an outer surface of the porous body of the liquid substance storing
container
10, 20, 30, 40 for vaporizing the liquid substance retained in the pores of
the porous
body.
The heater 52 may be a direct heating source such as a laser, a LED
(Light Emitting Diode), a flame or a heating resistance.
The heater 52 may also be an indirect source such as a flowing or
stagnant air which has been heated.
Generally, the heater 53 is an electrical heating element and is powered
by a battery 55.
The vaporized liquid substance is routed via flow channels (not
illustrated) from the vaporization chamber 54 to the mouth piece 52, crossing
preferably a filter 56 disposed upstream from a output 52a of the mouth piece
52.
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Of course, this embodiment of the aerosol generating device is not
!imitative.
In particular, when the porous body 41 has a hollow shape as depicted
in Figures 4A and 4B, the heater may be adapted to heat an inner surface 45a
of the
hollow porous body 41.
Thus, the heater may be configured to fit into the hole 45 of the porous
body 41. The heater is in contact with the internal surface 45a of the hole 45
for heat
conduction to the porous body 41. Preferably, the external surface of the
heater
matches the internal surface 45a of the hole 45 of the porous body 41 of the
liquid
substrate storing container 40.
Thanks to the invention, an improved liquid substance storing container
may be provided as a consumable for an electronic cigarette, with a higher
liquid
content rate compared to a consumable having the same overall volume and a
homogeneous porous body, without internal cavity.
Due to the improved packing efficiency, smaller storing container may be
formed, compared to a homogeneous porous body without closed internal cavity,
for
a predetermined volume of vaporizable liquid substance.
Alternatively, for a predetermined envelope or overall volume of the
porous body, a higher volume of vaporizable liquid substance may be stored in
the
storing container thanks to the presence of the closed internal cavity.
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