FIELD
[0001] The present disclosure relates to a heating system and an aerosol generating apparatus.
BACKGROUND
[0002] A typical aerosol generating apparatus may comprise a power supply, an aerosol generating
unit that is driven by the power supply, an aerosol precursor, which in use is aerosolised
by the aerosol generating unit to generate an aerosol, and a delivery system for delivery
of the aerosol to a user. A drawback with known aerosol generating apparatuses is
that a sensory effect for the user may diminish over the extended use of a consumable.
[0003] In spite of the effort already invested in the development of aerosol generating
apparatuses/systems further improvements are desirable.
SUMMARY
[0004] According to a first aspect, the present disclosure provides a heating system for
an aerosol generating apparatus for heating a consumable that comprises a plurality
of heating sections and a plurality of thermally insulating barriers, wherein the
heating sections and the thermally insulating barriers are alternatingly arranged.
[0005] In some examples, the plurality of heating sections may be arranged to heat a consumable
in a unique radial section along the longitudinal extension of the consumable, and
the plurality of heating sections and the plurality of thermally insulating barriers
may form a cavity having a uniform inner surface for accommodating a consumable.
[0006] According to a second aspect, the present disclosure further provides an aerosol
generating apparatus comprising a heating system according to the present disclosure.
[0007] In some examples each heating section may be arranged to independently heat a unique
radial section of a consumable inserted in the cavity, and more than one heating section
may be activated during a particular smoking cycle.
[0008] According to a third aspect, the present disclosure further provides a use of heating
system according to the present disclosure for heating a consumable in an aerosol
generating apparatus. According to a fourth aspect, the present disclosure still further
provides a method of manufacturing a heating system, wherein the heating system is
manufactured as an integral element by the steps of providing and/or positioning the
heating sections and performing a moulding step. In some examples, the moulding step
comprises moulding the thermally insulating barriers so that a heating section of
the plurality of heating sections is form-fittingly received between two thermally
insulating barriers.
[0009] According to a fifth aspect, the present disclosure still further provides a method
of manufacturing a heating system, wherein the heating system is manufactured as an
integral element by the steps of providing and/or positioning the heating sections
and performing a moulding step. In some examples, the moulding step comprises moulding
the thermally insulating barriers, a first end and a second end, so that a heating
section of the plurality of heating sections is form-fittingly received between the
first end, the second end and two thermally insulating barriers.
[0010] The present disclosure relates to heating a consumable for an aerosol generating
apparatus. The consumable may comprise flavour material or tobacco material that is
heated without burning. Flavour and/or nicotine is released by heating of the tobacco
material while generating substances as a result of a burning the tobacco material
are avoided. Still, when heating tobacco material, a depletion effect occurs in that
flavour and/or nicotine content of a particular part of the tobacco material of the
consumable is reduced while further substances generated by the heating of the tobacco
material are enriched within the consumable. In order to obtain a smoking experience,
air is drawn through the heated consumable material, so that the air is enriched with
flavour and/or nicotine when flowing through the consumable. A user of the aerosol
generating apparatus subsequently inhaled the air that has passed through the heated
consumable material in order to get a sensory experience.
[0011] Repeated drawing of air through the same heated consumable material may result in
the aforementioned depletion effect of flavour and/or nicotine while enriching the
consumable material by the aforementioned side products of the material heating. As
such, a difference sensory experience may be provided to a user throughout a smoking
cycle, i.e., a usage cycle of a consumable or a part of a consumable, where the air
passing through the heated consumable material substantially continues to move through
the same material part. A single smoking cycle may in particular be a cycle where
a user experiences a single nicotine payload, e.g., comparable to the nicotine payload
of a common cigarette.
[0012] In case not a complete consumable is heated at a particular time, the aforementioned
depletion and enrichment effects may only occur in the heated part of the consumable.
Thus, in case the heating is switched from heating at one part of the consumable material
to a further, previously unheated part of the consumable material, the sensory experience
for a user may sufficiently be as if the consumable has not been heated previously.
In other words, heating only a part of the consumable material may allow to provide
a user with a renewed smoking experience or sensory experience when switching from
a heated part of the consumable to a non-heated part. Preferably in accordance with
the present disclosure, a consumable is heated in a defined radial section of the
consumable, thereby providing a single heated air flow path through the entire length
of the consumable. Thereby, when switching from one radial section to be heated to
a further radial section to be heated, essentially the completed previously heated
section may be removed from the air flow path. In other words, by heating radial sections,
it is achievable to avoid having air drawn into the consumable to pass through a previously
heated section of the consumable as would be the case if the consumable is heated
at different sections along the longitudinal extension, corresponding to the airflow
through the consumable.
[0013] E.g., the heating system of the present disclosure may allow heating a consumable
in two separate radial sections, which would then essentially correspond to two half
circles. Such may be achieved by providing a heating system having two heating elements
each exhibiting a half-moon shape heating sections. Two heating sections and thus
two heating elements may be separated by an insulating barrier, so to avoid spreading
of the heat energy from one heating section to a further heated session.
[0014] Contrary hereto, with longitudinally split heater zones or heating sections, either
the top heating section or the bottom, considering a flow direction of air through
the consumable, may be used first. If the top is used first, then when the second
zone is used, the consumer will be drawing through the already used, possibly burnt
section of tobacco. If the bottom heater zone is used first, then there will be heating
of the top section of tobacco, possibly depleting some active ingredients, before
it is desired.
[0015] In the arrangement of the present disclosure, i.e., radially split heating sections,
the direction of airflow through the consumable will not impact the other section(s),
either by heating them due to hot airflow, or by masking the tobacco flavour with
burnt taste.
[0016] Each heating section may heat a section or part of the outer surface of the consumable
independently. The thermally insulating barrier may be arranged to avoid heat transfer,
i.e., bleeding of heat used to heat one heating section of the outer surface of the
consumable into the other heating section(s) of the outer surface of the consumable.
The heating sections of the consumable may be switched within one smoking cycle to
provide "fresh" tobacco material in the course of consuming the consumable.
[0017] Alternatively, a particular heating section of the consumable may be seen to correspond
to tobacco material for one smoking cycle, so that a consumable can be used for a
plurality of smoking cycles, without the other smoking experience(s) being influenced
by the previous smoking cycle. In other words, in this example, a unique radial section
may correspond to consumable, e.g., tobacco, material for one smoking cycle, so that
a consumable may be used for a plurality of smoking cycles, without the smoking experience
of a subsequent smoking cycle being influenced by the previous smoking cycle.
[0018] A uniform inner surface may be understood as a substantially flat, even or a gapless
inner surface, at least in defined parts or sections of the inner surface. In other
words, as long as the inner surface is sectionally uniform, the whole of the inner
surface may be understood as uniform. E.g., an example of a complete uniform inner
surface may be a circular, conical or oval inner surface. Examples of sectionally
uniform inner surfaces may one with three corners or bends, e.g., a triangular shaped
inner surface, four corners or bends, e.g., a quadratic or rectangular shaped inner
surface, five corners or bends, e.g., a pentagon shaped uniform inner surface, six
corners or bends, e.g., a hexagon shaped uniform inner surface. Similarly, further
uniform inner surfaces may exhibit a heptagon shape, octagon shape etc. The sides
between corners may be straight or continuously curved.
[0019] The heating sections may comprise or consist of a material with a high thermal conductivity,
e.g. a metal, like steel, stainless steel or copper. An individually controllable
heating element or a part of a larger heating element spanning multiple heating sections
and commonly heating the heating sections, e.g., a resistive heater track or an infrared
heater element, may be arranged adjacent to and or in contact with a particular heating
section. The heating element may be arranged radially outward from the inner surface
of the heating sections, so to heat the material of the heating section from the far
side of the inner surface. The high heat conductivity of the heating section allows
the transfer of the heat energy to the section of the consumable arranged adjacent
to and radially inward of the inner surface of the particular heating section.
[0020] The provision of a thermally insulating barrier between two adjacent heating sections
limits or prohibits the heat transfer between heating sections. The thermally insulating
barrier may comprise or consist of a material with a low thermal conductivity, e.g.
plastics, like PEEK, ceramics, carbon-based material, carbon fibre-based material
or glass.
[0021] Preferably, both the material of the heating sections and of the thermally insulating
barriers exhibits a smooth surface and/or has non-stick properties, in particular
when considering materials commonly used in a consumable, like paper, tobacco or aerosol-generating
filler material.
[0022] In order to generate an aerosol, the aerosol-forming material comprises at least
one volatile compound that is intended to be vaporised/aerosolised and that may provide
the user with a recreational and/or medicinal effect when inhaled. Suitable chemical
and/or physiologically active volatile compounds include the group consisting of:
nicotine, cocaine, caffeine, opiates and opoids, cathine and cathinone, kavalactones,
mysticin, beta-carboline alkaloids, salvinorin A together with any combinations, functional
equivalents to, and/or synthetic alternatives of the foregoing.
[0023] The aerosol-forming material may comprise plant material. The plant material may
comprise least one plant material selected from the list including Amaranthus dubius,
Arctostaphylos uva-ursi (Bearberry), Argemone mexicana, Amica, Artemisia vulgaris,
Yellow Tees, Galea zacatechichi, Canavalia maritima (Baybean), Cecropia mexicana (Guamura),
Cestrum noctumum, Cynoglossum virginianum (wild comfrey), Cytisus scoparius, Damiana,
Entada rheedii, Eschscholzia califomica (California Poppy), Fittonia albivenis, Hippobroma
longiflora, Humulus japonica (Japanese Hops), Humulus lupulus (Hops), Lactuca virosa
(Lettuce Opium), Laggera alata, Leonotis leonurus, Leonurus cardiaca (Motherwort),
Leonurus sibiricus (Honeyweed), Lobelia cardinalis, Lobelia inflata (Indian-tobacco),
Lobelia siphilitica, Nepeta cataria (Catnip), Nicotiana species (Tobacco), Nymphaea
alba (White Lily), Nymphaea caerulea (Blue Lily), Opium poppy, Passiflora incamata
(Passionflower), Pedicularis densiflora (Indian Warrior), Pedicularis groenlandica
(Elephant's Head), Salvia divinorum, Salvia dorrii (Tobacco Sage), Salvia species
(Sage), Scutellaria galericulata, Scutellaria lateriflora, Scutellaria nana, Scutellaria
species (Skullcap), Sida acuta (Wireweed), Sida rhombifolia, Silene capensis, Syzygium
aromaticum (Clove), Tagetes lucida (Mexican Tarragon), Tarchonanthus camphoratus,
Tumera diffusa (Damiana), Verbascum (Mullein), Zamia latifolia (Maconha Brava) together
with any combinations, functional equivalents to, and/or synthetic alternatives of
the foregoing.
[0024] In preferred embodiments, the aerosol-forming material comprises tobacco which will
contain nicotine as a volatile compound. Any type of tobacco may be used. This includes,
but is not limited to, flue-cured tobacco, burley tobacco, Maryland Tobacco, dark-air
cured tobacco, oriental tobacco, dark-fired tobacco, perique tobacco and rustica tobacco.
This also includes blends of the above-mentioned tobaccos. Any suitable parts of the
tobacco plant may be used. This includes leaves, stems, roots, bark, seeds and flowers.
The aerosol-forming material may comprise one or more of leaf tobacco, stem tobacco,
tobacco powder, tobacco dust, tobacco derivatives, expanded tobacco, shredded tobacco,
homogenised tobacco, extruded tobacco, cut rag tobacco and/or reconstituted tobacco
(e.g. slurry recon or paper recon).
[0025] According to the present disclosure a method of manufacturing the heating system
is proposed. In particular, it is proposed to manufacture the heating system by moulding
the thermally insulating barriers so that the material of the thermally insulating
material of the thermally insulating barriers is essentially surrounding and/or holding
the heating elements. In other words, the heating sections can be first arranged and/or
positioned so that they are in a relative position and/or spatial arrangement to one
another, corresponding to their final position relative to one another in the heating
system. Once heating sections are accordingly arranged, a moulding step is performed
where the material of the thermally insulating barriers is moulded around or at least
partially or selectively around the circumference of the heating sections. The material
of the thermally insulating barriers may thereby constitute a frame or support structure
holding the heating sections in place relative to one another while engaging with
the heating sections in a form fit. The resulting heating system may in particular
be an integral part formed by the heating sections and the thermally insulating barriers.
Potentially, the heating system comprises additional elements made of the same thermally
insulating material as the thermally insulating barriers. E.g., the additional elements
may be a first end and a second end, so that each heating section is surrounded on
four sides/around its circumference by the material of the thermally insulating barriers.
[0026] According to an embodiment of the present disclosure, the cavity may comprise a uniform
cylindrical inner surface so that an inserted part of a circular cylindrically shaped
consumable is arranged to be in surface contact with the inner cylindrical surface
of the cavity across substantially the entirety of the inserted part.
[0027] By providing a uniform, in other words a substantially flat, even or a gapless inner
cylindrical surface, the surface contact between the inner cylindrical surface and
the outside surface or outer surface of the consumable may be maximized. Thereby,
a heat transfer between a particular heating section and the respective surface section,
radial surface section of the consumable may be maximized.
[0028] According to a further embodiment of the present disclosure, the cavity may comprise
a uniform conical inner surface so that an inserted part of a circular cylindrically
shaped consumable is arranged to be in surface contact with the inner cylindrical
surface of the cavity across substantially the entirety of the inserted part.
[0029] By providing a uniform conical inner surface, preferably one where the diameter distant
from an initial receiving opening is smaller than the diameter proximal to the initial
receiving opening, an inserted consumable may experience progressively reduced cross-sectional
area when being inserted into the cavity, therefore experiencing an increased surface
contact with the inner surface distal from the initial receiving opening. Potentially,
the consumable material may even be (slightly) compressed when the cross-sectional
area of the cavity approximates or goes below the cross-sectional area of the consumable
in that region of the cavity. The initial receiving opening may be an opening that
is arranged at the outside of the housing of the aerosol generating apparatus.
[0030] The cavity may thus exhibit a slightly conical shape and may thus be tapered or a
truncated cone. The angle of a vector parallel to the inner surface of the cavity
and a vector parallel to the longitudinal extension of the cylindrical cavity, i.e.,
a vector parallel to the height in case the cavity resembles a truncated cone, is
less than 20°, in particular less than 15°, less than 10°, less than 9°, less than
8°, less than 7°, less than 6°, less than 5°, less than 4°, less than 3°, less than
2° or substantially 1°.
[0031] According to a further embodiment of the present disclosure, the heating system may
comprise two, three, four, five, six, seven, eight, nine, ten, eleven, twelve or more
heating sections and thermally insulating barriers.
[0032] According to a further embodiment of the present disclosure, each heating section
may be arranged to independently heat a unique radial section of a consumable.
[0033] According to a further embodiment of the present disclosure, not all heating sections
may be activated during a particular smoking cycle, in particular only one half, one
third, one fourth, one fifth, one sixth, one seventh, one eighth, one nineth, one
tenth, one eleventh or one twelfth of all heating sections may be activated during
a particular smoking cycle.
[0034] Providing an according number of heating sections and insulating barriers may allow
the provision of a comparable number of independently heatable heating sections. Thus,
such a number of heating sections may allow to independently heat a comparable number
of unique radial sections of a consumable. E.g., two heating sections may allow the
provision of a consumable intended for two smoking cycles so that one half of the
consumable is heated by one heating section during the first smoking cycle and the
second half of the consumable is heated by the other heating section during the second
smoking cycle. Thereby, used consumable material from the first smoking cycle may
not or may only marginally impact the sensory experience of a user during the second
smoking cycle. Such a mode of operation may potentially be implemented using more
than two heating sections.
[0035] Alternatively, or additionally, it may be conceivable to switch heating sections
within one smoking cycle so that during the smoking cycle, the user experiences a
renewed sensory experience from unused consumable material.
[0036] Still further, it may be conceivable that each uniquely heatable radial section of
a consumable corresponds to a defined number of puffs. E.g., in case it is intended
that a unique radial section corresponds to two puffs, an aerosol generating apparatus
having 12 independently heatable heating sections allows to provide a total of 24
puffs. Seen another way, in case 12 puffs correspond to a particular smoking cycle,
an aerosol generating apparatus having 12 independently heatable heating section would
allow to provide substantially fresh consumable material of a unique radial section
for each puff of a smoking cycle.
[0037] A particular preferable embodiment may be one with two, three or four independent
heating sections. Further, it may be preferable that with a consumable having a plurality
of unique radial sections, only non-adjacent radial sections may be heated consecutively.
[0038] According to a further embodiment of the present disclosure, each thermally insulating
barrier may be arranged to reduce or prohibit heat transfer from a particular heating
section from an adjacent or a further heating section.
[0039] By providing such a thermally insulating barrier, the heat impact of one heating
sections onto adjacent or further heating sections may be reduced or substantially
prevented. Thereby, it may be assured that heating of one unique radial section of
a consumable does not unnecessarily deplete or otherwise impact a further unique radial
section of the consumable, which is currently not intended to be heated. In other
words, the thermally insulating barrier may avoid "bleeding" of heat of one heating
section into a further heating section.
[0040] According to a further embodiment of the present disclosure, each heating section
may comprise a heating element and a heat transfer element, wherein the heat transfer
element is arranged adjacent to the heating element and oriented towards the cavity,
wherein the heat transfer element is arranged to receive heat energy from the heating
element and propagate the heat energy towards the cavity, and wherein the heat transfer
element constitutes the inner surface section of said particular heating section.
[0041] According to a further embodiment of the present disclosure, the heat transfer element
may be arranged to transfer the heat energy of the heating element of a particular
heating section to a particular radial section of a consumable, in particular to distribute
evenly the heat energy of the heating element over the surface of the radial section
of the inserted part of the consumable. Such a heat transfer element may allow the
heat distribution from a heating element which may be of a smaller size than the surface
of a particular unique radial heating section. In case of such a heating element that
would be in direct or close contact with the surface of the consumable, such could
result in an uneven heating of the surface of the consumable. Such an uneven heating
may result in consumable material not being heated uniformly in a particular unique
radial section. A heat transfer element that distributes localized heat generated
by a heating element across the substantially full surface of the consumable surface
contributes to an even heating of the consumable material of a particular radial section.
[0042] The heat transfer element may in particular be a heat transfer layer having a comparably
small thickness.
[0043] According to a further embodiment of the present disclosure, the plurality of heating
sections and the plurality of thermally insulating barriers may be arranged so not
to unevenly alter the surface shape of a consumable inserted in the cavity.
[0044] In other words, the inner surfaces of the heating sections and the thermally insulating
barriers are provided in a substantially continuous manner. E.g., assuming a circular
cylindrical shape of the cavity, the inner surfaces of the heating sections and the
thermally insulating barriers may comprise similar or identical circular sectors having
similar or identical radii.
[0045] According to a further embodiment of the present disclosure, the ratio of the surface
area of the plurality of heating sections to the total inner surface area of the cavity
may be 0,9, greater than 0,9, 0,91, 0,92, 0,93, 0,94, 0,95, greater than 0,95, 0,96,
0,97, 0,98, 0,99, greater than 0,99, or substantially 1.
[0046] Having a higher ratio of surface area of the heating section compared to a thermally
insulating barrier allows to avoid a significant reduction in heat exposure of consumable
material in the area of the thermally insulating barriers. In other words, a comparably
slim thermally insulating barrier, while prohibiting a direct heat transfer from one
heating section to an adjacent heating section, may still allow sufficient heat exposure
for the consumable material to substantially heat the complete unique radial section
of the consumable, thereby avoiding that on heated or less heated consumable material
exists in the area of the thermally insulating barriers between heating sections.
[0047] According to a further embodiment of the present disclosure, the heating system may
be manufactured as an integral element by providing and positioning the heating sections,
performing a moulding step, wherein the moulding step comprises moulding the thermally
insulating barriers so that a heating section of the plurality of heating sections
is form-fittingly received between two thermally insulating barriers.
[0048] Optionally, the heating system may be manufactured as an integral element by providing
and positioning the heating sections, performing a moulding step, wherein the moulding
step comprises moulding the thermally insulating barriers, a first end, and a second
end, so that a heating section of the plurality of heating sections is form-fittingly
received between the first end, the second end and two thermally insulating barriers.
[0049] According to a further embodiment of the present disclosure, the more than one heating
sections activated during a particular smoking cycle may be activated in parallel,
successively, may be phased in, may be phased out and/or a heating section may be
phased in while a further heating section may be phased out.
[0050] By activating, potentially on user demand, more than one heating sections and thus
heating more than one unique radial sections of a consumable, exposure of the user
to flavour and/or nicotine may be increased. E.g., a user may determine that they
prefer a stronger smoking experience and thus the aerosol generating apparatus may
be set to heat to radial section simultaneously. Alternatively, or additionally, the
heating of a particular unique radial section may be phased out while the heating
of a further unique radial section may be phased in, so that potentially the exposure
of the user to flavour and/or nicotine remains substantially constant. In other words,
while one unique radial section gets progressively depleted, said depletion is compensated
by providing flavour and/or nicotine from a further unique radial section. Alternatively,
only a further radial section may be phased in since the already heated radial section
is effectively phased out by its being depleted, without actually requiring phasing
out the heating of the respective unique radial section.
[0051] According to a further embodiment of the present disclosure, a particular heating
section of the plurality of heating sections may be switched on or phased in or switched
off or phased out dependent on a number of detected puffs within a particular smoking
cycle.
[0052] In other words, it is conceivable that the aerosol generating apparatus detects a
number of paths conducted by the user and dependent on a defined number of puffs per
week radial section of a consumable, the heating sections may be controlled. E.g.,
in case a particular unique radial section of a consumable is intended for four puffs,
the heating section corresponding to said unique radial section may be switched off
or phased out after four puffs while the heating section of a further unique radial
section may be switched on or phased in.
[0053] According to a further embodiment of the present disclosure, the aerosol generating
apparatus may be arranged to direct an airflow through the consumable so that the
airflow is generally directed, in particular substantially limited to passing through
the heated section of the consumable, while limiting or substantially prohibiting
passing through the non-heated section of the consumable.
[0054] Thereby, it may be avoided that air is passing through non-heated consumable material,
which may not contribute to providing the user with a sufficient sensory experience
since unheated consumable material may not provide the desired flavour and/or nicotine
exposure to the user. According to a further embodiment of the present disclosure,
the aerosol generating apparatus may be arranged to allow insertion of a particular
consumable only in a defined unique radial position. In other words, an unintended
rotation of the consumable may be avoided. Thereby, a user may remove a consumable
where not all unique radial sections of the consumable have been heated previously
and may reinsert the same consumable while maintaining the same radial position. Thereby,
it may be avoided that already heated consumable material is reheated again and/or
that a consumable is considered depleted where not all unique radial sections have
already been heated. Preferably, also the consumable is adapted so that it can only
be inserted into the cavity in a defined unique radial orientation.
[0055] The preceding summary is provided for purposes of summarizing some examples to provide
a basic understanding of aspects of the subject matter described herein. Accordingly,
the above-described features should not be construed to narrow the scope or spirit
of the subject matter described herein in any way. Moreover, the above and/or proceeding
examples may be combined in any suitable combination to provide further examples,
except where such a combination is clearly impermissible or expressly avoided. Other
features, aspects, and advantages of the subject matter described herein will become
apparent from the following text and the accompanying drawings.
BRIEF DESCRIPTION OF THE FIGURES
[0056] Aspects, features and advantages of the present disclosure will become apparent from
the following description of examples in reference to the appended drawings in which
like numerals denote like elements.
Fig. 1 is a block system diagram showing an example aerosol generating apparatus.
Fig. 2 is an exemplary embodiment of a heating system according to the present disclosure.
Figs. 3a and 3b are further exemplary embodiments of a heating system according to the present disclosure.
Fig. 4 is a block system diagram showing an example implementation of the apparatus of
Fig. 1, where the aerosol generating apparatus is configured to generate aerosol from
a solid precursor.
Fig. 5 is a schematic diagram showing an example implementation of the apparatus of Fig.
4.
Figs. 6a to 6d are further views of exemplary embodiments heating system according to the present
disclosure.
DETAILED DESCRIPTION OF EMBODIMENTS
[0057] Before describing several examples implementing the present disclosure, it is to
be understood that the present disclosure is not limited by specific construction
details or process steps set forth in the following description and accompanying drawings.
Rather, it will be apparent to those skilled in the art having the benefit of the
present disclosure that the systems, apparatuses and/or methods described herein could
be embodied differently and/or be practiced or carried out in various alternative
ways.
[0058] Unless otherwise defined herein, scientific and technical terms used in connection
with the presently disclosed inventive concept(s) shall have the meanings that are
commonly understood by those of ordinary skill in the art, and known techniques and
procedures may be performed according to conventional methods well known in the art
and as described in various general and more specific references that may be cited
and discussed in the present specification.
[0059] Any patents, published patent applications, and non-patent publications mentioned
in the specification are hereby incorporated by reference in their entirety.
[0060] All examples implementing the present disclosure can be made and executed without
undue experimentation in light of the present disclosure. While particular examples
have been described, it will be apparent to those of skill in the art that variations
may be applied to the systems, apparatus, and/or methods and in the steps or in the
sequence of steps of the methods described herein without departing from the concept,
spirit, and scope of the inventive concept(s). All such similar substitutions and
modifications apparent to those skilled in the art are deemed to be within the spirit,
scope, and concept of the inventive concept(s) as defined by the appended claims.
The use of the term "a" or "an" in the claims and/or the specification may mean "one,"
as well as "one or more," "at least one," and "one or more than one." As such, the
terms "a," "an," and "the," as well as all singular terms, include plural referents
unless the context clearly indicates otherwise. Likewise, plural terms shall include
the singular unless otherwise required by context.
[0061] The use of the term "or" in the present disclosure (including the claims) is used
to mean an inclusive "and/or" unless explicitly indicated to refer to alternatives
only or unless the alternatives are mutually exclusive. For example, a condition "A
or B" is satisfied by any of the following: A is true (or present), and B is false
(or not present), A is false (or not present), and B is true (or present), and both
A and B are true (or present).
[0062] As used in this specification and claim(s), the words "comprising, "having," "including,"
or "containing" (and any forms thereof, such as "comprise" and "comprises," "have"
and "has," "includes" and "include," or "contains" and "contain," respectively) are
inclusive or open-ended and do not exclude additional, unrecited elements or method
steps.
[0063] Unless otherwise explicitly stated as incompatible, or the physics or otherwise of
the embodiments, examples, or claims prevent such a combination, the features of examples
disclosed herein, and of the claims, may be integrated together in any suitable arrangement,
especially ones where there is a beneficial effect in doing so. This is not limited
to only any specified benefit, and instead may arise from an "ex post facto" benefit.
This is to say that the combination of features is not limited by the described forms,
particularly the form (e.g., numbering) of example(s), embodiment(s), or dependency
of claim(s). Moreover, this also applies to the phrase "in one embodiment," "according
to an embodiment," and the like, which are merely a stylistic form of wording and
are not to be construed as limiting the following features to a separate embodiment
to all other instances of the same or similar wording. This is to say, a reference
to `an,' 'one,' or 'some' embodiment(s) may be a reference to any one or more, and/or
all embodiments, or combination(s) thereof, disclosed. Also, similarly, the reference
to "the" embodiment may not be limited to the immediately preceding embodiment. Further,
all references to one or more embodiments or examples are to be construed as non-limiting
to the claims. The present disclosure may be better understood in view of the following
explanations, wherein the terms used that are separated by "or" may be used interchangeably:
[0064] As used herein, an "
aerosol generating apparatus" (or "
electronic(e)-cigarette") may be an apparatus configured to deliver an aerosol to a user for inhalation by
the user. The apparatus may additionally/alternatively be referred to as a "smoking
substitute apparatus", if it is intended to be used instead of a conventional combustible
smoking article. As used herein a combustible "smoking article" may refer to a cigarette,
cigar, pipe or other article, that produces smoke (an aerosol comprising solid particulates
and gas) via heating above the thermal decomposition temperature (typically by combustion
and/or pyrolysis). An aerosol generated by the apparatus may comprise an aerosol with
particle sizes of 0.2 - 7 microns, or less than 10 microns, or less than 7 microns.
This particle size may be achieved by control of one or more of: heater temperature;
cooling rate as the vapour condenses to an aerosol; flow properties including turbulence
and velocity. The generation of aerosol by the aerosol generating apparatus may be
controlled by an input device. The input device may be configured to be user-activated
and may for example include or take the form of an actuator (e.g., actuation button)
and/or an airflow sensor.
[0065] Each occurrence of the aerosol generating apparatus being caused to generate aerosol
for a period of time (which may be variable) may be referred to as an "
activation" of the aerosol generating apparatus. The aerosol generating apparatus may be arranged
to allow an amount of aerosol delivered to a user to be varied per activation (as
opposed to delivering a fixed dose of aerosol), e.g. by activating an aerosol generating
unit of the apparatus for a variable amount of time, e.g. based on the strength/duration
of a draw of a user through a flow path of the apparatus (to replicate an effect of
smoking a conventional combustible smoking article).
[0066] The aerosol generating apparatus may be portable. As used herein, the term "
portable" may refer to the apparatus being for use when held by a user.
[0067] As used herein, an "
aerosol generating system" may be a system that includes an aerosol generating apparatus and optionally other
circuitry/components associated with the function of the apparatus, e.g., one or more
external devices and/or one or more external components (here "external" is intended
to mean external to the aerosol generating apparatus). As used herein, an "external
device" and "external component" may include one or more of a: a charging device,
a mobile device (which may be connected to the aerosol generating apparatus, e.g.,
via a wireless or wired connection); a networked-based computer (e.g., a remote server);
a cloud-based computer; any other server system.
[0068] An example aerosol generating system may be a system for managing an aerosol generating
apparatus. Such a system may include, for example, a mobile device, a network server,
as well as the aerosol generating apparatus.
[0069] As used herein, an "
aerosol" may include a suspension of precursor, including as one or more of: solid particles;
liquid droplets; gas. Said suspension may be in a gas including air. An aerosol herein
may generally refer to/include a vapour. An aerosol may include one or more components
of the precursor.
[0070] As used herein, a "
precursor" may include one or more of a: liquid; solid; gel; loose leaf material; other substance.
The precursor may be processed by an aerosol generating unit of an aerosol generating
apparatus to generate an aerosol. The precursor may include one or more of: an active
component; a carrier; a flavouring. The active component may include one or more of
nicotine; caffeine; a cannabidiol oil; a non-pharmaceutical formulation, e.g., a formulation
which is not for treatment of a disease or physiological malfunction of the human
body. The active component may be carried by the carrier, which may be a liquid, including
propylene glycol and/or glycerine. The term "flavouring" may refer to a component
that provides a taste and/or a smell to the user. The flavouring may include one or
more of: Ethylvanillin (vanilla); menthol, Isoamyl acetate (banana oil); or other.
The precursor may include a substrate, e.g., reconstituted tobacco to carry one or
more of the active component; a carrier; a flavouring. The precursor correspond to
the consumable material.
[0071] As used herein, a "
storage portion" may be a portion of the apparatus adapted to store the precursor. It may be implemented
as fluid-holding reservoir or carrier for solid material depending on the implementation
of the precursor as defined above.
[0072] As used herein, a "
flow path" may refer to a path or enclosed passageway through an aerosol generating apparatus,
e.g., for delivery of an aerosol to a user. The flow path may be arranged to receive
aerosol from an aerosol generating unit. When referring to the flow path, upstream
and downstream may be defined in respect of a direction of flow in the flow path,
e.g., with an outlet being downstream of an inlet.
[0073] As used herein, a "
delivery system" may be a system operative to deliver an aerosol to a user. The delivery system may
include a mouthpiece and a flow path.
[0074] As used herein, a "
flow" may refer to a flow in a flow path. A flow may include aerosol generated from the
precursor. The flow may include air, which may be induced into the flow path via a
puff by a user.
[0075] As used herein, a "
puff" (or "
inhale" or "
draw") by a user may refer to expansion of lungs and/or oral cavity of a user to create
a pressure reduction that induces flow through the flow path.
[0076] As used herein, an "
aerosol generating unit" may refer to a device configured to generate an aerosol from a precursor. The aerosol
generating unit may include a unit to generate a vapour directly from the precursor
(e.g., a heating system or other system) or an aerosol directly from the precursor
(e.g., an atomiser including an ultrasonic system, a flow expansion system operative
to carry droplets of the precursor in the flow without using electrical energy or
other system). A plurality of aerosol generating units to generate a plurality of
aerosols (for example, from a plurality of different aerosol precursors) may be present
in an aerosol generating apparatus.
[0077] As used herein, a "
heating system" may refer to an arrangement of at least one heating element, which is operable to
aerosolise a precursor once heated. The at least one heating element may be electrically
resistive to produce heat from the flow of electrical current therethrough. The at
least one heating element may be arranged as a susceptor to produce heat when penetrated
by an alternating magnetic field. The heating system may be configured to heat a precursor
to below 300 or 350 degrees C, including without combustion.
[0078] As used herein, a "
consumable" may refer to a unit that includes a precursor. The consumable may include an aerosol
generating unit, e.g., it may be arranged as a cartomizer. The consumable may include
a mouthpiece. The consumable may include an information carrying medium. With liquid
or gel implementations of the precursor, e.g., an e-liquid, the consumable may be
referred to as a "capsule" or a "pod" or an "e-liquid consumable". The capsule/pod
may include a storage portion, e.g., a reservoir or tank, for storage of the precursor.
With solid material implementations of the precursor, e.g., tobacco or reconstituted
tobacco formulation, the consumable may be referred to as a "stick" or "package" or
"heat-not-burn consumable". In a heat-not-burn consumable, the mouthpiece may be implemented
as a filter and the consumable may be arranged to carry the precursor. The consumable
may be implemented as a dosage or pre-portioned amount of material, including a loose-leaf
product.
[0079] As used herein, an "
information carrying medium" may include one or more arrangements for storage of information on any suitable
medium. Examples include: a computer readable medium; a Radio Frequency Identification
(RFID) transponder; codes encoding information, such as optical (e.g., a bar code
or QR code) or mechanically read codes (e.g., a configuration of the absence or presents
of cut-outs to encode a bit, through which pins or a reader may be inserted).
[0080] As used herein "
heat-not-burn" (or "
HNB" or "
heated precursor") may refer to the heating of a precursor, typically tobacco, without combustion,
or without substantial combustion (i.e., localised combustion may be experienced of
limited portions of the precursor, including of less than 5% of the total volume).
[0081] Referring to Fig. 1, an example aerosol generating apparatus 1 includes a power supply
2, for supply of electrical energy. The apparatus 1 includes an aerosol generating
unit 4 that is driven by the power supply 2. The power supply 2 may include an electric
power supply in the form of a battery and/or an electrical connection to an external
power source. The apparatus 1 includes a precursor 6, which in use is aerosolised
by the aerosol generating unit 4 to generate an aerosol. The apparatus 2 includes
a delivery system 8 for delivery of the aerosol to a user.
[0082] Electrical circuitry (not shown in Fig. 1) may be implemented to control the interoperability
of the power supply 4 and aerosol generating unit 6.
[0083] In variant examples, which are not illustrated, the power supply 2 may be omitted
since, e.g., an aerosol generating unit implemented as an atomiser with flow expansion
may not require a power supply.
[0084] Fig. 2 shows an exemplary embodiment of a heating system according to the present
disclosure. Fig. 2 depicts a heating system 20 having exemplarily two heating sections
22a,b, which are separated by two thermally insulating barriers 24. Each heating section
22a,b has a generally semi-circular shape and thus constitutes half of a circular
cylindrical structure. The heating sections 22a,b form a cavity 28 for receiving a
consumable 70.
[0085] The dimensions of the thermally insulating barriers 24 compared to the dimensions
of the heating sections 22a,b are comparably small so that each heating section 22a,b
heats substantially half of the surface of an inserted consumable, while the regions
on the surface of the consumable that coincide with the thermally insulating barriers
24 may be neglectable. In other words, a potentially reduced heating of the regions
on the surface of the consumable that coincide with the thermally insulating barriers
24 may not significantly impact the smoking experience of a user of an aerosol generating
apparatus 1 using such a heating system 20. Each heating section 22a,b thus corresponds
to a unique radial section of the consumable 70 and is heating the respective adjacent
unique radial section thereof. A first end 30a of the heating system 20 may correspond
to the end being arranged towards the outside of an aerosol generating apparatus 1
having such a heating system 20. The first end 30a may thus be seen as having the
receiving opening of the cavity 28 where a consumable 70 is inserted into the heating
system 20. The first end 30a is thus arranged proximal to the outside of the housing
of an aerosol generating apparatus 1. Heating system 20 comprises a further, second
end 30b, which can also be referred to as the distal end when seen from the receiving
opening of cavity 28.
[0086] The heating system 20 has a longitudinal extension, exemplified by arrow 26. Arrow
26 essentially corresponds to an air flow direction through a consumable 70 inserted
into the cavity 28 of the heating system 20.
[0087] The heating sections 22a,b may in particular be independently heatable so that the
respective unique radial sections of the consumable are independently heatable as
well.
[0088] Figs. 3a and 3b show exemplary embodiments of a heating system according to the present
disclosure.
[0089] Fig. 3a corresponds to the heating system 20 of Fig. 2, however has four heating
sections 22a,b,c,d, as well as four thermally insulating barriers 24. In the embodiment
of Fig. 3, each heating section 22a,b,c,d exhibits a generally quarter circle shape
for heating one of four unique radial sections of a consumable 70.
[0090] Fig. 3b in turn depicts a heating system having eight heating sections 22a-h and
eight thermally insulating barriers 24. As such, each heating section may thus heat
one of eight unique radial sections of a consumable 70, where each unique radial section
corresponds to a radial section of 1/8
th of the consumable. The dimension of a thermally insulating barrier 24 to a single
such heating section 22a-h or radial section may still be in a collectible so that
each heating section 22a-h substantially uniformly heats its adjacent radial section
of 1/8
th of the consumable. In other words, in the embodiment of Fig 3b, or even in embodiments
with e.g., 10 or 12 heating sections, a single heating section may substantially completely
and uniformly heat its adjacent radial section of 1/8
th (or 1/10
th or 1/12
th) of the consumable 70.
[0091] Fig. 4 shows an implementation of the apparatus 1 of Fig. 1, where the aerosol generating
apparatus 1 is configured to generate aerosol by a-heat not-burn process.
[0092] In this example, the apparatus 1 includes a device body 50 and a consumable 70.
[0093] In this example, the body 50 includes the power supply 4 and a heating system 52.
The heating system 54 includes at least one heating element 54. The body may additionally
include any one or more of electrical circuitry 56, a memory 58, a wireless interface
60, one or more other components 62.
[0094] The electrical circuitry 56 may include a processing resource for controlling one
or more operations of the body 50, e.g., based on instructions stored in the memory
58.
[0095] The wireless interface 60 may be configured to communicate wirelessly with an external
(e.g., mobile) device, e.g., via Bluetooth.
[0096] The other component(s) 62 may include an actuator, one or more user interface devices
configured to convey information to a user and/or a charging port, for example (see
e.g., Fig. 5). The body 50 is configured to engage with the consumable 70 such that
the at least one heating element 54 of the heating system 52 penetrates into the solid
precursor 6 of the consumable. In use, a user may activate the aerosol generating
apparatus 1 to cause the heating system 52 of the body 50 to cause the at least one
heating element 54 to heat the solid precursor 6 of the consumable (without combusting
it) by conductive heat transfer, to generate an aerosol which is inhaled by the user.
[0097] Fig. 5 shows an example implementation of the aerosol generating apparatus 1 of Fig.
4.
[0098] As depicted in Fig. 5, the consumable 70 is implemented as a stick, which is engaged
with the body 50 by inserting the stick into an aperture at a top end 53 of the body
50, which causes the at least one heating element 54 of the heating system 52 to penetrate
into the solid precursor 6. The consumable 70 includes the solid precursor 6 proximal
to the body 50, and a filter distal to the body 50. The filter serves as the mouthpiece
of the consumable 70 and thus the apparatus 1 as a whole. The solid precursor 6 may
be a reconstituted tobacco formulation.
[0099] In this example, the at least one heating element 54 is a rod-shaped element with
a circular transverse profile. Other heating element shapes are possible, e.g., the
at least one heating element may be blade-shaped (with a rectangular transverse profile)
or tube-shaped (e.g., with a hollow transverse profile).
[0100] In this example, the body 50 includes a cap 51. In use the cap 51 is engaged at a
top end 53 of the body 50. Although not apparent from Fig. 5, the cap 51 is moveable
relative to the body 50. In particular, the cap 51 is slidable and can slide along
a longitudinal axis of the body 50.
[0101] The body 50 also includes an actuator 55 on an outer surface of the body 50. In this
example, the actuator 55 has the form of a button.
[0102] The body 50 also includes a user interface device configured to convey information
to a user. Here, the user interface device is implemented as a plurality of lights
57, which may e.g., be configured to illuminate when the apparatus 1 is activated
and/or to indicate a charging state of the power supply 4. Other user interface devices
are possible, e.g., to convey information haptically or audibly to a user.
[0103] The body may also include an airflow sensor which detects airflow in the aerosol
generating apparatus 1 (e.g., caused by a user inhaling through the consumable 70).
This may be used to count puffs, for example.
[0104] In this example, the consumable 70 includes a flow path which transmits aerosol generated
by the at least one heating element 54 to the mouthpiece of the consumable. The longitudinal
extension 26 of the consumable 70 corresponds to the longitudinal extension 26 of
the heating system 20, and may also indicate the air flow path of air drawn through
the consumable 70 by a user of the aerosol generating apparatus 1.
[0105] In this example, the aerosol generating unit 4 is provided by the above-described
heating system 52 and the delivery system 8 is provided by the above-described flow
path and mouthpiece of the consumable 70.
[0106] Figs. 6a to 6d are further views of exemplary embodiments heating system according
to the present disclosure.
[0107] Fig. 6a shows a cross sectional view cut through a plane perpendicular to the longitudinal
axis of the heating system 20, having two heating sections 22a,b and two thermally
insulating barriers 24.
[0108] Fig. 6b shows a cross sectional view cut through a plane parallel to the longitudinal
axis of the heating system 20, having two heating sections 22a,b and two thermally
insulating barriers 24.
[0109] Fig. 6c shows a perspective view of the heating system 20, having two heating sections
22a,b and two thermally insulating barriers 24.
[0110] Here, the heating sections 22a,b essentially have the shape of a semi-circle, so
that two heating sections seen together essentially form a circular shape. As such,
each heating section 22a,b has two essentially straight sides 102 and two essentially
circular sides, here semi-circular 104 forming the respective circumference. When
the heating sections are put together on their essentially straight sides 102, they
form the aforementioned circular shape. The two thermally insulating barriers 24 are
arranged between the straight sides 102, thereby holding a positioning the heating
sections 22a,b at a defined relative position to one another, spaced apart by the
thermally insulating barriers 24. In other words, the thermally insulating barriers
24 fill the gap between the heating sections 22a,b and they are in their intended
or defined position relative to one another. Further depicted in Fig. 6a is a first
end 100a, which may be made of the same thermally insulating material as the thermally
insulating barriers 24. By arranging the heating sections 22a,b in a position relative
to one another that they are supposed to assume in the final heating system 20, the
material forming the thermally insulating barriers 24 including the first end 100a
and a further second end 100b as depicted in Figs. 6b to d, may be provided in a moulding
step, where the thermally insulating barriers 24, the first end 100a and the second
end 100b are moulded in a single step around the circumference of the heating sections
22a,b, in other words around the two straight sides 102 and the two semi-circular
sides 104 forming the circumference of each heating section 22a,b. The thermally insulating
barriers are thus arranged at a 180° angle relative to one another.
[0111] By moulding the thermally insulating material of the thermally insulating barriers
24 and the first and second and 100a,b, the heating sections 22a,b are received within
the material around the circumference, such that they are held in place by the thermally
insulating material in a form fit. As such, an integral part consisting of the heating
sections, the thermally insulating barriers and the first and second end is formed.
[0112] Fig. 6b shows an exemplary embodiment of where the curved sides 104 of the heating
sections 22a,b are received by the first and second and in a notch 106. The notch
106 contributes to the form fit between the heating sections and the thermally insulating
material. As such, after the moulding step, the heating sections are held in place
by the thermally insulating material without requiring a further measures or elements.
[0113] Fig. 6c shows the entire integral part of the exemplary embodiment of a heating system
20 comprising two heating sections 22a,b, two insulating barriers 24 and two ends
110a,b.
[0114] Fig. 6d shows a perspective view of the heating system 20, having four heating sections
22a,b,c,d and four thermally insulating barriers 24.
[0115] The essential difference between the heating system 20 of Fig. 6d and the heating
system 20 as depicted in Figs. 6a-c is that the circular sides 104 of each heating
section 22a,b,c,d comprises the shape of a quarter circle, rather than that of a semicircle.
As a consequence, the thermally insulating barriers 24 are thus arranged at a 90°
angle relative to one another compared to the 180° angle relative to one another as
with the embodiment of Figs. 6a-c.
1. A heating system (20) for an aerosol generating apparatus (1) for heating a consumable
(70), comprising
a plurality of heating sections (22a-h), and
a plurality of thermally insulating barriers (24),
wherein the heating sections and the thermally insulating barriers are alternatingly
arranged,
wherein the plurality of heating sections (22a-h) are arranged to heat a consumable
(70) in a unique radial section along the longitudinal extension of the consumable,
and
wherein the plurality of heating sections and the plurality of thermally insulating
barriers form a cavity having a uniform inner surface for accommodating a consumable.
2. The heating system according to the preceding claim,
wherein the cavity comprises a uniform cylindrical inner surface so that an inserted
part of a cylindrically shaped consumable is arranged to be in surface contact with
the inner cylindrical surface of the cavity across substantially the entirety of the
inserted part, or
wherein the cavity comprises a uniform conical inner surface so that an inserted part
of a circular cylindrically shaped consumable is arranged to be in surface contact
with the inner cylindrical surface of the cavity across substantially the entirety
of the inserted part.
3. The heating system according to at least one of the preceding claims,
wherein the heating system comprises two, three, four, five, six, seven, eight, nine,
ten, eleven, twelve or more heating sections and thermally insulating barriers.
4. The heating system according to at least one of the preceding claims,
wherein each heating section is arranged to independently heat a unique radial section
of a consumable.
5. The heating system according to at least one of the preceding claims,
wherein each thermally insulating barrier is arranged to reduce or prohibit heat transfer
from a particular heating section from an adjacent or a further heating section.
6. The heating system according to at least one of the preceding claims,
wherein each heating section comprises
a heating element and
a heat transfer element,
wherein the heat transfer element is arranged adjacent to the heating element and
oriented towards the cavity,
wherein the heat transfer element is arranged to receive heat energy from the heating
element and propagate the heat energy towards the cavity, and
wherein the heat transfer element constitutes the inner surface section of said particular
heating section,
wherein the heat transfer element is arranged to transfer the heat energy of the heating
element of a particular heating section to a particular radial section of a consumable,
in particular to distribute evenly the heat energy of the heating element over the
surface of the radial section of the inserted part of the consumable.
7. The heating system according to at least one of the preceding claims,
wherein the plurality of heating sections and the plurality of thermally insulating
barriers are arranged so not to unevenly alter the surface shape of a consumable inserted
in the cavity.
8. The heating system according to at least one of the preceding claims,
wherein the ratio of the surface area of the plurality of heating sections to the
total inner surface area of the cavity is 0,9, greater than 0,9, 0,91, 0,92, 0,93,
0,94, 0,95, greater than 0,95, 0,96, 0,97, 0,98, 0,99, greater than 0,99, or substantially
1.
9. The heating system according to at least one of the preceding claims,
wherein the heating system (20) is manufactured as an integral element by
providing and/or positioning the heating sections (22a-h),
performing a moulding step,
wherein the moulding step comprises
moulding the thermally insulating barriers (24) so that a
heating section (22a-h) of the plurality of heating sections (22a-h)
is form-fittingly received between two thermally insulating barriers
(24).
10. An aerosol generating apparatus comprising a heating system according to at least
one of the preceding claims,
wherein each heating section is arranged to independently heat a unique radial section
of a consumable inserted in the cavity, and
wherein more than one heating section is activated during a particular smoking cycle.
11. The aerosol generating apparatus according to the preceding claim,
wherein the more than one heating sections activated during a particular smoking cycle
are activated in parallel, successively, are phased in, are phased out or a heating
section is phased in while a further heating section is phased out.
12. The aerosol generating apparatus according to at least one of the preceding claims,
wherein a particular heating section of the plurality of heating sections is switched
on or phased in or switched off or phased out dependent on a number of detected puffs
within a particular smoking cycle.
13. The aerosol generating apparatus according to at least one of the preceding claims,
wherein not all heating sections are activated during a particular smoking cycle,
in particular only one half, one third, one fourth, one fifth, one sixth, one seventh,
one eighth, one nineth, one tenth, one eleventh or one twelfth of all heating sections
are activated during a particular smoking cycle.
14. The aerosol generating apparatus according to at least one of the preceding claims,
wherein the aerosol generating apparatus is arranged to direct an airflow through
the consumable so that the airflow is generally directed, in particular substantially
limited to passing through the heated section of the consumable, while limiting or
substantially prohibiting passing through the non-heated section of the consumable.
15. Method of manufacturing a heating system (20), wherein the heating system (20) is
manufactured as an integral element by the steps of
providing and/or positioning the heating sections (22a-h), and
performing a moulding step,
wherein the moulding step comprises
moulding the thermally insulating barriers (24) so that a heating section (22a-h)
of the plurality of heating sections (22a-h) is form-fittingly received between two
thermally insulating barriers (24).