U.S. patent application number 17/696467 was filed with the patent office on 2022-06-30 for smoking substitute apparatus.
The applicant listed for this patent is Nerudia Limited. Invention is credited to Nikhil AGGARWAL, Benjamin ASTBURY, Dean COWAN, Andrew DUCKWORTH, Benjamin ILLIDGE, Peter LOMAS.
Application Number | 20220202075 17/696467 |
Document ID | / |
Family ID | 1000006251706 |
Filed Date | 2022-06-30 |
United States Patent
Application |
20220202075 |
Kind Code |
A1 |
ILLIDGE; Benjamin ; et
al. |
June 30, 2022 |
SMOKING SUBSTITUTE APPARATUS
Abstract
A smoking substitute system comprises: a main body and a smoking
substitute apparatus. The smoking substitute apparatus comprises: a
housing; an air inlet at a first end of the housing and an air
outlet; an air flow channel between the air inlet and the air
outlet through the housing; and an aerosol generator to generate an
aerosol, the aerosol generator located in the air flow channel
downstream of the air inlet. The main body comprises: a main body
housing configured to couple to the housing of the smoking
substitute apparatus; a main body air inlet to the housing; a
plenum chamber within the main body housing to receive airflow from
the main body air inlet; wherein the plenum chamber is within the
main body housing at a position upstream of the air inlet of the
smoking substitute apparatus when the main body housing is coupled
to the smoking substitute apparatus.
Inventors: |
ILLIDGE; Benjamin;
(Livepool, GB) ; ASTBURY; Benjamin; (Livepool,
GB) ; AGGARWAL; Nikhil; (Livepool, GB) ;
DUCKWORTH; Andrew; (Livepool, GB) ; LOMAS; Peter;
(Liverpool, GB) ; COWAN; Dean; (Liverpool,
GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Nerudia Limited |
Liverpool |
|
GB |
|
|
Family ID: |
1000006251706 |
Appl. No.: |
17/696467 |
Filed: |
March 16, 2022 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/EP2020/076269 |
Sep 21, 2020 |
|
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17696467 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A24F 40/44 20200101;
A24F 40/46 20200101; A24F 40/10 20200101; A24F 40/50 20200101 |
International
Class: |
A24F 40/10 20060101
A24F040/10; A24F 40/44 20060101 A24F040/44; A24F 40/50 20060101
A24F040/50; A24F 40/46 20060101 A24F040/46 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 20, 2019 |
EP |
19198630.6 |
Sep 20, 2019 |
EP |
19198635.5 |
Sep 20, 2019 |
EP |
19198649.6 |
Claims
1. A smoking substitute system comprising: a main body; and a
smoking substitute apparatus; the smoking substitute apparatus
comprising: a housing; an air inlet provided at a first end of the
housing and an air outlet; an air flow channel between the air
inlet and the air outlet through the housing; and an aerosol
generator configured to generate an aerosol from an aerosol
precursor, wherein the aerosol generator is located in the air flow
channel at a position downstream of the air inlet along the air
flow channel; the main body comprising: a main body housing which
is configured to physically couple to the housing of the smoking
substitute apparatus; a main body air inlet to the housing; a
plenum chamber within the main body housing, the plenum chamber
configured to receive airflow from the main body air inlet; wherein
the plenum chamber is provided within the main body housing at a
position which is directly upstream of the air inlet of the smoking
substitute apparatus when the main body housing is coupled to the
smoking substitute apparatus.
2. A smoking substitute system according to claim 1, wherein the
plenum chamber is provided as a void within the main body of the
housing.
3. A smoking substitute system according to claim 1 or 2, wherein
the main body has a first cross-sectional area and the plenum
chamber has a second cross-sectional area, and wherein a ratio of
the second cross-sectional area to the first cross-sectional area,
expressed as a percentage, taken at the same position along a
longitudinal axis of the main body, is at least 70%, optionally at
least 80%, optionally at least 90%.
4. A smoking substitute system according to any one of the
preceding claims, wherein the plenum chamber has an axial length of
at least 5 mm.
5. A smoking substitute system according to any one of the
preceding claims, wherein the main body has a longitudinal axis and
the plenum chamber extends in an axial direction, and wherein the
main body air inlet is located in a sidewall of the housing
adjacent to an upstream end of the plenum chamber.
6. A smoking substitute system according to any one of claims 1 to
4, wherein the main body has a longitudinal axis, and wherein the
main body air inlet is offset from the plenum chamber in an axial
direction with an airflow path between the main body air inlet and
the plenum chamber passing through the main body housing.
7. A smoking substitute system according to any one of the
preceding claims, wherein the first end of the housing of the
smoking substitute apparatus has a first cross-sectional area and
the air inlet of the smoking substitute apparatus has a second
cross-sectional area, and wherein a ratio of the second
cross-sectional area to the first cross-sectional area, expressed
as a percentage, taken at the same position along a longitudinal
axis of the smoking substitute apparatus, is at least 70%,
optionally at least 80%, optionally at least 90%.
8. A smoking substitute system according to any of the preceding
claims, comprising: one or more electrical contacts provided on the
housing of the smoking substitute apparatus and electrically
connected with the aerosol generator; one or more electrical
contacts provided on the main body which are configured to engage
with corresponding electrical contacts on the smoking substitute
apparatus, wherein the one or more electrical contacts provided on
the housing of the smoking substitute apparatus are located beyond
a perimeter of the air inlet of the smoking substitute
apparatus.
9. A smoking substitute system according to claim 8, wherein the
one or more electrical contacts of the smoking substitute apparatus
are located on an outer surface of the sidewall of the housing of
the smoking substitute apparatus.
10. A main body for a smoking substitute system comprising the main
body and a smoking substitute apparatus, the main body comprising:
a housing which is configured to physically couple to the smoking
substitute apparatus; an air inlet to the housing; a plenum chamber
within the housing, the plenum chamber configured to receive
airflow from the air inlet; wherein the plenum chamber is provided
within the housing at a position which is directly upstream of an
air inlet of the smoking substitute apparatus when the main body
housing is coupled to the smoking substitute apparatus.
11. A main body according to claim 10, wherein the main body has a
longitudinal axis and the plenum chamber extends in an axial
direction, and wherein the main body air inlet is located in a
sidewall of the housing adjacent to an upstream end of the plenum
chamber.
12. A main body according to claim 10, wherein the main body has a
longitudinal axis, and wherein the main body air inlet is offset
from the plenum chamber in an axial direction with an airflow path
between the main body air inlet and the plenum chamber passing
through the main body housing.
13. A main body according to any one of claims 10 to 12, comprising
one or more electrical contacts which are configured to engage with
corresponding electrical contacts of the smoking substitute
apparatus, wherein the one or more electrical contacts of the main
body are located on a sidewall of the housing of the main body.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS/INCORPORATION BY REFERENCE
STATEMENT
[0001] This application is a non-provisional application claiming
benefit to the international application no. PCT/EP2020/076269
filed on Sep. 21, 2020, which claims priority to EP 19198635.5
filed on Sep. 20, 2019, EP 19198630.6 filed on Sep. 20, 2019, and
EP 19198649.6 filed on Sep. 20, 2019. The entire contents of each
of the above-referenced applications are hereby incorporated herein
by reference in their entirety.
FIELD OF THE DISCLOSURE
[0002] The present disclosure relates to a smoking substitute
apparatus and, in particular, a smoking substitute apparatus that
is able to deliver nicotine to a user in an effective manner.
BACKGROUND
[0003] The smoking of tobacco is generally considered to expose a
smoker to potentially harmful substances. It is thought that a
significant amount of the potentially harmful substances are
generated through the burning and/or combustion of the tobacco and
the constituents of the burnt tobacco in the tobacco smoke
itself.
[0004] Low temperature combustion of organic material such as
tobacco is known to produce tar and other potentially harmful
by-products. There have been proposed various smoking substitute
systems in which the conventional smoking of tobacco is
avoided.
[0005] Such smoking substitute systems can form part of nicotine
replacement therapies aimed at people who wish to stop smoking and
overcome a dependence on nicotine.
[0006] Known smoking substitute systems include electronic systems
that permit a user to simulate the act of smoking by producing an
aerosol (also referred to as a "vapor") that is drawn into the
lungs through the mouth (inhaled) and then exhaled. The inhaled
aerosol typically bears nicotine and/or a flavorant without, or
with fewer of, the health risks associated with conventional
smoking.
[0007] In general, smoking substitute systems are intended to
provide a substitute for the rituals of smoking, whilst providing
the user with a similar, or improved, experience and satisfaction
to those experienced with conventional smoking and with combustible
tobacco products.
[0008] The popularity and use of smoking substitute systems has
grown rapidly in the past few years. Although originally marketed
as an aid to assist habitual smokers wishing to quit tobacco
smoking, consumers are increasingly viewing smoking substitute
systems as desirable lifestyle accessories. There are a number of
different categories of smoking substitute systems, each utilizing
a different smoking substitute approach. Some smoking substitute
systems are designed to resemble a conventional cigarette and are
cylindrical in form with a mouthpiece at one end. Other smoking
substitute devices do not generally resemble a cigarette (for
example, the smoking substitute device may have a generally
box-like form, in whole or in part).
[0009] One approach is the so-called "vaping" approach, in which a
vaporizable liquid, or an aerosol former, sometimes typically
referred to herein as "e-liquid", is heated by a heating device
(sometimes referred to herein as an electronic cigarette or
"e-cigarette" device) to produce an aerosol vapor which is inhaled
by a user. The e-liquid typically includes a base liquid, nicotine
and may include a flavorant. The resulting vapor therefore also
typically contains nicotine and/or a flavorant. The base liquid may
include propylene glycol and/or vegetable glycerin.
[0010] A typical e-cigarette device includes a mouthpiece, a power
source (typically a battery), a tank for containing e-liquid and a
heating device. In use, electrical energy is supplied from the
power source to the heating device, which heats the e-liquid to
produce an aerosol (or "vapor") which is inhaled by a user through
the mouthpiece.
[0011] E-cigarettes can be configured in a variety of ways. For
example, there are "closed system" vaping smoking substitute
systems, which typically have a sealed tank and heating element.
The tank is pre-filled with e-liquid and is not intended to be
refilled by an end user. One subset of closed system vaping smoking
substitute systems include a main body which includes the power
source, wherein the main body is configured to be physically and
electrically couplable to a consumable including the tank and the
heating element. In this way, when the tank of a consumable has
been emptied of e-liquid, that consumable is removed from the main
body and disposed of. The main body can then be reused by
connecting it to a new, replacement, consumable. Another subset of
closed system vaping smoking substitute systems are completely
disposable, and intended for one-use only.
[0012] There are also "open system" vaping smoking substitute
systems which typically have a tank that is configured to be
refilled by a user. In this way the entire device can be used
multiple times.
[0013] An example vaping smoking substitute system is the myblu.TM.
e-cigarette. The myblu.TM. e-cigarette is a closed system which
includes a main body and a consumable. The main body and consumable
are physically and electrically coupled together by pushing the
consumable into the main body. The main body includes a
rechargeable battery. The consumable includes a mouthpiece and a
sealed tank which contains e-liquid. The consumable further
includes a heater, which for this device is a heating filament
coiled around a portion of a wick. The wick is partially immersed
in the e-liquid, and conveys e-liquid from the tank to the heating
filament. The system is controlled by a microprocessor on board the
main body. The system includes a sensor for detecting when a user
is inhaling through the mouthpiece, the microprocessor then
activating the device in response. When the system is activated,
electrical energy is supplied from the power source to the heating
device, which heats e-liquid from the tank to produce a vapor which
is inhaled by a user through the mouthpiece.
SUMMARY OF THE DISCLOSURE
[0014] For a smoking substitute system, it is desirable to deliver
nicotine into the user's lungs, where it can be absorbed into the
bloodstream. However, the present disclosure is based in part on a
realization that some prior art smoking substitute systems, such
delivery of nicotine is not efficient. In some prior art systems,
the aerosol droplets have a size distribution that is not suitable
for delivering nicotine to the lungs. Aerosol droplets of a large
particle size tend to be deposited in the mouth and/or upper
respiratory tract. Aerosol particles of a small (e.g., sub-micron)
particle size can be inhaled into the lungs but may be exhaled
without delivering nicotine to the lungs. As a result, the user
would require drawing a longer puff, more puffs, or vaporizing
e-liquid with a higher nicotine concentration in order to achieve
the desired experience.
[0015] Accordingly, there is a need for improvement in the delivery
of nicotine to a user in the context of a smoking substitute
system.
Development A
[0016] The present disclosure (Development A) has been devised in
the light of the above considerations.
[0017] In a general aspect of Development A, the present disclosure
relates to a smoking substitute system comprising a main body and a
smoking substitute apparatus with a plenum chamber provided within
the main body.
[0018] According to a first preferred aspect of Development A there
is provided a smoking substitute system comprising: a main body;
and a smoking substitute apparatus; the smoking substitute
apparatus comprising: a housing; an air inlet provided at a first
end of the housing and an air outlet; an air flow channel between
the air inlet and the air outlet through the housing; and an
aerosol generator configured to generate an aerosol from an aerosol
precursor, wherein the aerosol generator is located in the air flow
channel at a position downstream of the air inlet along the air
flow channel; the main body comprising: a main body housing which
is configured to physically couple to the housing of the smoking
substitute apparatus; a main body air inlet to the housing; a
plenum chamber within the main body housing, the plenum chamber
configured to receive airflow from the main body air inlet; wherein
the plenum chamber is provided within the main body housing at a
position which is directly upstream of the air inlet of the smoking
substitute apparatus when the main body housing is coupled to the
smoking substitute apparatus.
[0019] The plenum chamber can reduce velocity of the air flow as
the incoming air flow is now distributed over a larger
cross-sectional area. An enlarged cross-sectional area of the air
inlet can help to provide a more even air flow to the aerosol
generator, such as a heater. The air flow may be less turbulent at
the aerosol generator. The above factors can help to increase
particle size of particles formed by the aerosol generator.
Providing the plenum chamber within the main body can reduce the
physical size of the smoking substitute apparatus, which may be a
consumable item. This can reduce the quantity of materials needed
to form the consumable item.
[0020] Optionally, the plenum chamber is provided as a void within
the main body of the housing.
[0021] Optionally, the main body has a first cross-sectional area
and the plenum chamber has a second cross-sectional area, and
wherein a ratio of the second cross-sectional area to the first
cross-sectional area, expressed as a percentage, taken at the same
position along a longitudinal axis of the main body, is at least
70%, optionally at least 80%, optionally at least 90%.
[0022] Optionally, the plenum chamber has an axial length of at
least 5 mm.
[0023] Optionally, the main body has a longitudinal axis and the
plenum chamber extends in an axial direction, and wherein the main
body air inlet is located in a sidewall of the housing adjacent to
an upstream end of the plenum chamber.
[0024] Optionally, the main body has a longitudinal axis, and
wherein the main body air inlet is offset from the plenum chamber
in an axial direction with an airflow path between the main body
air inlet and the plenum chamber passing through the main body
housing.
[0025] Optionally, the first end of the housing of the smoking
substitute apparatus has a first cross-sectional area and the air
inlet of the smoking substitute apparatus has a second
cross-sectional area, and wherein a ratio of the second
cross-sectional area to the first cross-sectional area, expressed
as a percentage, taken at the same position along a longitudinal
axis of the smoking substitute apparatus, is at least 70%,
optionally at least 80%, optionally at least 90%.
[0026] Optionally, the smoking substitute system comprises one or
more electrical contacts provided on the housing of the smoking
substitute apparatus and electrically connected with the aerosol
generator; one or more electrical contacts provided on the main
body which are configured to engage with corresponding electrical
contacts on the smoking substitute apparatus, wherein the one or
more electrical contacts provided on the housing of the smoking
substitute apparatus are located beyond a perimeter of the air
inlet of the smoking substitute apparatus.
[0027] Optionally, the one or more electrical contacts of the
smoking substitute apparatus are located on an outer surface of the
sidewall of the housing of the smoking substitute apparatus.
[0028] Another aspect of Development A provides a main body for a
smoking substitute system comprising the main body and a smoking
substitute apparatus, the main body comprising: a housing which is
configured to physically couple to the smoking substitute
apparatus; an air inlet to the housing; a plenum chamber within the
housing, the plenum chamber configured to receive airflow from the
air inlet; wherein the plenum chamber is provided within the
housing at a position which is directly upstream of an air inlet of
the smoking substitute apparatus when the main body housing is
coupled to the smoking substitute apparatus.
[0029] The plenum chamber can reduce velocity of the air flow as
the incoming air flow is now distributed over a larger
cross-sectional area. An enlarged cross-sectional area of the air
inlet can help to provide a more even air flow to the aerosol
generator, such as a heater. The air flow may be less turbulent at
the aerosol generator. The above factors can help to increase
particle size of particles formed by the aerosol generator.
Providing the plenum chamber within the main body can reduce the
physical size of the smoking substitute apparatus, which may be a
consumable item. This can reduce the quantity of materials needed
to form the consumable item.
[0030] Optionally, the main body has a longitudinal axis and the
plenum chamber extends in an axial direction, and wherein the main
body air inlet is located in a sidewall of the housing adjacent to
an upstream end of the plenum chamber.
[0031] Optionally, the main body has a longitudinal axis, and
wherein the main body air inlet is offset from the plenum chamber
in an axial direction with an airflow path between the main body
air inlet and the plenum chamber passing through the main body
housing.
[0032] Optionally, the main body comprises one or more electrical
contacts which are configured to engage with corresponding
electrical contacts of the smoking substitute apparatus, wherein
the one or more electrical contacts of the main body are located on
a sidewall of the housing of the main body.
[0033] There now follows a disclosure of various optional features.
These are intended to be applicable to Development A, disclosed
above, and may also be applied in any combination (unless the
context demands otherwise) to any aspect, embodiment or optional
feature set out with respect to Development B and/or Development
C.
[0034] The smoking substitute apparatus may be in the form of a
consumable. The consumable may be configured for engagement with a
main body. When the consumable is engaged with the main body, the
combination of the consumable and the main body may form a smoking
substitute system such as a closed smoking substitute system. For
example, the consumable may comprise components of the system that
are disposable, and the main body may comprise non-disposable or
non-consumable components (e.g., power supply, controller, sensor,
etc.) that facilitate the generation and/or delivery of aerosol by
the consumable. In such an embodiment, the aerosol precursor (e.g.,
e-liquid) may be replenished by replacing a used consumable with an
unused consumable.
[0035] Alternatively, the smoking substitute apparatus may be a
non-consumable apparatus (e.g., that is in the form of an open
smoking substitute system). In such embodiments an aerosol former
(e.g., e-liquid) of the system may be replenished by re-filling,
e.g., a reservoir of the smoking substitute apparatus, with the
aerosol precursor (rather than replacing a consumable component of
the apparatus).
[0036] In light of this, it should be appreciated that some of the
features described herein as being part of the smoking substitute
apparatus may alternatively form part of a main body for engagement
with the smoking substitute apparatus. This may be the case in
particular when the smoking substitute apparatus is in the form of
a consumable.
[0037] Where the smoking substitute apparatus is in the form of a
consumable, the main body and the consumable may be configured to
be physically coupled together. For example, the consumable may be
at least partially received in a recess of the main body, such that
there is an interference fit between the main body and the
consumable. Alternatively, the main body and the consumable may be
physically coupled together by screwing one onto the other, or
through a bayonet fitting, or the like.
[0038] Thus, the smoking substitute apparatus may comprise one or
more engagement portions for engaging with a main body. In this
way, one end of the smoking substitute apparatus may be coupled
with the main body, whilst an opposing end of the smoking
substitute apparatus may define a mouthpiece of the smoking
substitute system.
[0039] The smoking substitute apparatus may comprise a reservoir
configured to store an aerosol precursor, such as an e-liquid. The
e-liquid may, for example, comprise a base liquid. The e-liquid may
further comprise nicotine. The base liquid may include propylene
glycol and/or vegetable glycerin. The e-liquid may be substantially
flavorless. That is, the e-liquid may not contain any deliberately
added additional flavorant and may consist solely of a base liquid
of propylene glycol and/or vegetable glycerin and nicotine.
[0040] The reservoir may be in the form of a tank. At least a
portion of the tank may be light-transmissive. For example, the
tank may comprise a window to allow a user to visually assess the
quantity of e-liquid in the tank. A housing of the smoking
substitute apparatus may comprise a corresponding aperture (or
slot) or window that may be aligned with a light-transmissive
portion (e.g., window) of the tank. The reservoir may be referred
to as a "clearomizer" if it includes a window, or a "cartomizer" if
it does not.
[0041] The smoking substitute apparatus may comprise a passage for
fluid flow therethrough. The passage may extend through (at least a
portion of) the smoking substitute apparatus, between openings that
may define an inlet and an outlet of the passage. The outlet may be
at a mouthpiece of the smoking substitute apparatus. In this
respect, a user may draw fluid (e.g., air) into and through the
passage by inhaling at the outlet (i.e., using the mouthpiece). The
passage may be at least partially defined by the tank. The tank may
substantially (or fully) define the passage, for at least a part of
the length of the passage. In this respect, the tank may surround
the passage, e.g., in an annular arrangement around the
passage.
[0042] The smoking substitute apparatus may comprise an aerosol
generator. The aerosol generator may comprise a wick. The aerosol
generator may further comprise a heater. The wick may comprise a
porous material, capable of wicking the aerosol precursor. A
portion of the wick may be exposed to air flow in the passage. The
wick may also comprise one or more portions in contact with liquid
stored in the reservoir. For example, opposing ends of the wick may
protrude into the reservoir and an intermediate portion (between
the ends) may extend across the passage so as to be exposed to air
flow in the passage. Thus, liquid may be drawn (e.g., by capillary
action) along the wick, from the reservoir to the portion of the
wick exposed to air flow.
[0043] The heater may comprise a heating element, which may be in
the form of a filament wound about the wick (e.g., the filament may
extend helically about the wick in a coil configuration). The
heating element may be wound about the intermediate portion of the
wick that is exposed to air flow in the passage. The heating
element may be electrically connected (or connectable) to a power
source. Thus, in operation, the power source may apply a voltage
across the heating element so as to heat the heating element by
resistive heating. This may cause liquid stored in the wick (i.e.,
drawn from the tank) to be heated so as to form a vapor and become
entrained in air flowing through the passage. This vapor may
subsequently cool to form an aerosol in the passage, typically
downstream from the heating element.
[0044] The smoking substitute apparatus may comprise a vaporization
chamber. The vaporization chamber may form part of the passage in
which the heater is located. The vaporization chamber may be
arranged to be in fluid communication with the inlet and outlet of
the passage. The vaporization chamber may be an enlarged portion of
the passage. In this respect, the air as drawn in by the user may
entrain the generated vapor in a flow away from heater. The
entrained vapor may form an aerosol in the vaporization chamber, or
it may form the aerosol further downstream along the passage. The
vaporization chamber may be at least partially defined by the tank.
The tank may substantially (or fully) define the vaporization
chamber. In this respect, the tank may surround the vaporization
chamber, e.g., in an annular arrangement around the vaporization
chamber.
[0045] In use, the user may puff on a mouthpiece of the smoking
substitute apparatus, i.e., draw on the smoking substitute
apparatus by inhaling, to draw in an air stream therethrough. A
portion, or all, of the air stream (also referred to as a "main air
flow") may pass through the vaporization chamber so as to entrain
the vapor generated at the heater. That is, such a main air flow
may be heated by the heater (although typically only to a limited
extent) as it passes through the vaporization chamber.
Alternatively, or in addition, a portion of the air stream (also
referred to as a "dilution air flow" or "bypass air flow)) may
bypass the vaporization chamber and be directed to mix with the
generated aerosol downstream from the vaporization chamber. That
is, the dilution air flow may be an air stream at an ambient
temperature and may not be directly heated at all by the heater.
The dilution air flow may combine with the main air flow for
diluting the aerosol contained therein. The dilution air flow may
merge with the main air flow along the passage downstream from the
vaporization chamber. Alternatively, the dilution air flow may be
directly inhaled by the user without passing though the passage of
the smoking substitute apparatus.
[0046] As a user puffs on the mouthpiece, vaporized e-liquid
entrained in the passing air flow may be drawn towards the outlet
of the passage. The vapor may cool, and thereby nucleate and/or
condense along the passage to form a plurality of aerosol droplets,
e.g., nicotine-containing aerosol droplets. A portion of these
aerosol droplets may be delivered to and be absorbed at a target
delivery site, e.g., a user's lung, whilst a portion of the aerosol
droplets may instead adhere onto other parts of the user's
respiratory tract, e.g., the user's oral cavity and/or throat.
Typically, in some known smoking substitute apparatuses, the
aerosol droplets as measured at the outlet of the passage, e.g., at
the mouthpiece, may have a mean droplet size, d.sub.50, of less
than 1 .mu.m.
[0047] In some embodiments of the disclosure, the d.sub.50 particle
size of the aerosol particles is preferably at least 1 .mu.m.
Typically, the d.sub.50 particle size is not more than 10 .mu.m,
preferably not more than 9 .mu.m, not more than 8 .mu.m, not more
than 7 .mu.m, not more than 6 .mu.m, not more than 5 .mu.m, not
more than 4 .mu.m or not more than 3 .mu.m. It is considered that
providing aerosol particle sizes in such ranges permits improved
interaction between the aerosol particles and the user's lungs.
[0048] The particle droplet size, d.sub.50, of an aerosol may be
measured by a laser diffraction technique. For example, the stream
of aerosol output from the outlet of the passage may be drawn
through a Malvern Spraytec laser diffraction system, where the
intensity and pattern of scattered laser light are analyzed to
calculate the size and size distribution of aerosol droplets. As
will be readily understood, the particle size distribution may be
expressed in terms of d.sub.10, d.sub.50 and d.sub.90, for example.
Considering a cumulative plot of the volume of the particles
measured by the laser diffraction technique, the d.sub.10 particle
size is the particle size below which 10% by volume of the sample
lies. The d.sub.50 particle size is the particle size below which
50% by volume of the sample lies. The d.sub.90 particle size is the
particle size below which 90% by volume of the sample lies. Unless
otherwise indicated herein, the particle size measurements are
volume-based particle size measurements, rather than number-based
or mass-based particle size measurements.
[0049] The smoking substitute apparatus (or main body engaged with
the smoking substitute apparatus) may comprise a power source. The
power source may be electrically connected (or connectable) to a
heater of the smoking substitute apparatus (e.g., when the smoking
substitute apparatus is engaged with the main body). The power
source may be a battery (e.g., a rechargeable battery). A connector
in the form of, e.g., a USB port may be provided for recharging
this battery.
[0050] When the smoking substitute apparatus is in the form of a
consumable, the smoking substitute apparatus may comprise an
electrical interface for interfacing with a corresponding
electrical interface of the main body. One or both of the
electrical interfaces may include one or more electrical contacts.
Thus, when the main body is engaged with the consumable, the
electrical interface of the main body may be configured to transfer
electrical power from the power source to a heater of the
consumable via the electrical interface of the consumable.
[0051] The electrical interface of the smoking substitute apparatus
may also be used to identify the smoking substitute apparatus (in
the form of a consumable) from a list of known types. For example,
the consumable may have a certain concentration of nicotine and the
electrical interface may be used to identify this. The electrical
interface may additionally or alternatively be used to identify
when a consumable is connected to the main body.
[0052] Again, where the smoking substitute apparatus is in the form
of a consumable, the main body may comprise an identification
means, which may, for example, be in the form of an RFID reader, a
barcode or QR code reader. This identification means may be able to
identify a characteristic (e.g., a type) of a consumable engaged
with the main body. In this respect, the consumable may include any
one or more of an RFID chip, a barcode or QR code, or memory within
which is an identifier and which can be interrogated via the
identification means.
[0053] The smoking substitute apparatus or main body may comprise a
controller, which may include a microprocessor. The controller may
be configured to control the supply of power from the power source
to the heater of the smoking substitute apparatus (e.g., via the
electrical contacts). A memory may be provided and may be
operatively connected to the controller. The memory may include
non-volatile memory. The memory may include instructions which,
when implemented, cause the controller to perform certain tasks or
steps of a method.
[0054] The main body or smoking substitute apparatus may comprise a
wireless interface, which may be configured to communicate
wirelessly with another device, for example a mobile device, e.g.,
via Bluetooth.RTM.. To this end, the wireless interface could
include a Bluetooth.RTM. antenna. Other wireless communication
interfaces, e.g., WIFI.RTM., are also possible. The wireless
interface may also be configured to communicate wirelessly with a
remote server.
[0055] A puff sensor may be provided that is configured to detect a
puff (i.e., inhalation from a user). The puff sensor may be
operatively connected to the controller so as to be able to provide
a signal to the controller that is indicative of a puff state
(i.e., puffing or not puffing). The puff sensor may, for example,
be in the form of a pressure sensor or an acoustic sensor. That is,
the controller may control power supply to the heater of the
consumable in response to a puff detection by the sensor. The
control may be in the form of activation of the heater in response
to a detected puff. That is, the smoking substitute apparatus may
be configured to be activated when a puff is detected by the puff
sensor. When the smoking substitute apparatus is in the form of a
consumable, the puff sensor may be provided in the consumable or
alternatively may be provided in the main body.
[0056] The term "flavorant" is used to describe a compound or
combination of compounds that provide flavor and/or aroma. For
example, the flavorant may be configured to interact with a sensory
receptor of a user (such as an olfactory or taste receptor). The
flavorant may include one or more volatile substances.
[0057] The flavorant may be provided in solid or liquid form. The
flavorant may be natural or synthetic. For example, the flavorant
may include menthol, licorice, chocolate, fruit flavor (including,
e.g., citrus, cherry etc.), vanilla, spice (e.g., ginger, cinnamon)
and tobacco flavor. The flavorant may be evenly dispersed or may be
provided in isolated locations and/or varying concentrations.
[0058] The present inventors consider that a flow rate of 1.3 L
min.sup.-1 is towards the lower end of a typical user expectation
of flow rate through a conventional cigarette and therefore through
a user-acceptable smoking substitute apparatus. The present
inventors further consider that a flow rate of 2.0 L min.sup.-1 is
towards the higher end of a typical user expectation of flow rate
through a conventional cigarette and therefore through a
user-acceptable smoking substitute apparatus. Embodiments of the
present disclosure therefore provide an aerosol with advantageous
particle size characteristics across a range of flow rates of air
through the apparatus.
[0059] The aerosol may have a Dv50 of at least 1.1 .mu.m, at least
1.2 .mu.m, at least 1.3 .mu.m, at least 1.4 .mu.m, at least 1.5
.mu.m, at least 1.6 .mu.m, at least 1.7 .mu.m, at least 1.8 .mu.m,
at least 1.9 .mu.m or at least 2.0 .mu.m.
[0060] The aerosol may have a Dv50 of not more than 4.9 .mu.m, not
more than 4.8 .mu.m, not more than 4.7 .mu.m, not more than 4.6
.mu.m, not more than 4.5 .mu.m, not more than 4.4 .mu.m, not more
than 4.3 .mu.m, not more than 4.2 .mu.m, not more than 4.1 .mu.m,
not more than 4.0 .mu.m, not more than 3.9 .mu.m, not more than 3.8
.mu.m, not more than 3.7 .mu.m, not more than 3.6 .mu.m, not more
than 3.5 .mu.m, not more than 3.4 .mu.m, not more than 3.3 .mu.m,
not more than 3.2 .mu.m, not more than 3.1 .mu.m or not more than
3.0 .mu.m.
[0061] A particularly preferred range for Dv50 of the aerosol is in
the range 2-3 .mu.m.
[0062] The air inlet, flow passage, outlet and the vaporization
chamber may be configured so that, when the air flow rate inhaled
by the user through the apparatus is 1.3 L min.sup.-1, the average
magnitude of velocity of air in the vaporization chamber is in the
range 0-1.3 ms.sup.-1. The average magnitude velocity of air may be
calculated based on knowledge of the geometry of the vaporization
chamber and the flow rate.
[0063] When the air flow rate inhaled by the user through the
apparatus is 1.3 L min.sup.-1, the average magnitude of velocity of
air in the vaporization chamber may be at least 0.001 ms.sup.-1, or
at least 0.005 ms.sup.-1, or at least 0.01 ms.sup.-1, or at least
0.05 ms.sup.-1.
[0064] When the air flow rate inhaled by the user through the
apparatus is 1.3 L min.sup.-1, the average magnitude of velocity of
air in the vaporization chamber may be at most 1.2 ms.sup.-, at
most 1.1 ms.sup.-1, at most 1.0 ms.sup.-1, at most 0.9 ms.sup.-1,
at most 0.8 ms.sup.-1, at most 0.7 ms.sup.-1 or at most 0.6
ms.sup.-1.
[0065] The air inlet, flow passage, outlet and the vaporization
chamber may be configured so that, when the air flow rate inhaled
by the user through the apparatus is 2.0 L min.sup.-1, the average
magnitude of velocity of air in the vaporization chamber is in the
range 0-1.3 ms.sup.-1. The average magnitude velocity of air may be
calculated based on knowledge of the geometry of the vaporization
chamber and the flow rate.
[0066] When the air flow rate inhaled by the user through the
apparatus is 2.0 L min.sup.-1, the average magnitude of velocity of
air in the vaporization chamber may be at least 0.001 ms.sup.-1, or
at least 0.005 ms.sup.-1, or at least 0.01 ms.sup.-1, or at least
0.05 ms.sup.-1.
[0067] When the air flow rate inhaled by the user through the
apparatus is 2.0 L min.sup.-1, the average magnitude of velocity of
air in the vaporization chamber may be at most 1.2 ms.sup.-1, at
most 1.1 ms.sup.-1, at most 1.0 ms.sup.-1, at most 0.9 ms.sup.-1,
at most 0.8 ms.sup.-1, at most 0.7 ms.sup.-1 or at most 0.6
ms.sup.-1.
[0068] When the calculated average magnitude of velocity of air in
the vaporization chamber is in the ranges specified, it is
considered that the resultant aerosol particle size is
advantageously controlled to be in a desirable range. It is further
considered that the configuration of the apparatus can be selected
so that the average magnitude of velocity of air in the
vaporization chamber can be brought within the ranges specified, at
the exemplary flow rate of 1.3 L min.sup.-1 and/or the exemplary
flow rate of 2.0 L min.sup.-1.
[0069] The aerosol generator may comprise a vaporizer element
loaded with aerosol precursor, the vaporizer element being heatable
by a heater and presenting a vaporizer element surface to air in
the vaporization chamber. A vaporizer element region may be defined
as a volume extending outwardly from the vaporizer element surface
to a distance of 1 mm from the vaporizer element surface.
[0070] The air inlet, flow passage, outlet and the vaporization
chamber may be configured so that, when the air flow rate inhaled
by the user through the apparatus is 1.3 L min.sup.-1, the average
magnitude of velocity of air in the vaporizer element region is in
the range 0-1.2 ms.sup.-1. The average magnitude of velocity of air
in the vaporizer element region may be calculated using
computational fluid dynamics.
[0071] When the air flow rate inhaled by the user through the
apparatus is 1.3 L min.sup.-1, the average magnitude of velocity of
air in the vaporizer element region may be at least 0.001
ms.sup.-1, or at least 0.005 ms.sup.-1, or at least 0.01 ms.sup.-1,
or at least 0.05 ms.sup.-1.
[0072] When the air flow rate inhaled by the user through the
apparatus is 1.3 L min.sup.-1, the average magnitude of velocity of
air in the vaporizer element region may be at most 1.1 ms.sup.-1,
at most 1.0 ms.sup.-1, at most 0.9 ms.sup.-1, at most 0.8
ms.sup.-1, at most 0.7 ms.sup.-1 or at most 0.6 ms.sup.-1.
[0073] The air inlet, flow passage, outlet and the vaporization
chamber may be configured so that, when the air flow rate inhaled
by the user through the apparatus is 2.0 L min.sup.-1, the average
magnitude of velocity of air in the vaporizer element region is in
the range 0-1.2 ms.sup.-1. The average magnitude of velocity of air
in the vaporizer element region may be calculated using
computational fluid dynamics.
[0074] When the air flow rate inhaled by the user through the
apparatus is 2.0 L min.sup.-1, the average magnitude of velocity of
air in the vaporizer element region may be at least 0.001
ms.sup.-1, or at least 0.005 ms.sup.-1, or at least 0.01 ms.sup.-1,
or at least 0.05 ms.sup.-1.
[0075] When the air flow rate inhaled by the user through the
apparatus is 2.0 L min.sup.-1, the average magnitude of velocity of
air in the vaporizer element region may be at most 1.1 ms.sup.-1,
at most 1.0 ms.sup.-1, at most 0.9 ms.sup.-1, at most 0.8
ms.sup.-1, at most 0.7 ms.sup.-1 or at most 0.6 ms.sup.-1.
[0076] When the average magnitude of velocity of air in the
vaporizer element region is in the ranges specified, it is
considered that the resultant aerosol particle size is
advantageously controlled to be in a desirable range. It is further
considered that the velocity of air in the vaporizer element region
is more relevant to the resultant particle size characteristics
than consideration of the velocity in the vaporization chamber as a
whole. This is in view of the significant effect of the velocity of
air in the vaporizer element region on the cooling of the vapor
emitted from the vaporizer element surface.
[0077] Additionally, or alternatively, it is relevant to consider
the maximum magnitude of velocity of air in the vaporizer element
region.
[0078] Therefore, the air inlet, flow passage, outlet and the
vaporization chamber may be configured so that, when the air flow
rate inhaled by the user through the apparatus is 1.3 L min.sup.-1,
the maximum magnitude of velocity of air in the vaporizer element
region is in the range 0-2.0 ms.sup.-1.
[0079] When the air flow rate inhaled by the user through the
apparatus is 1.3 L min.sup.-1, the maximum magnitude of velocity of
air in the vaporizer element region may be at least 0.001
ms.sup.-1, or at least 0.005 ms.sup.-1, or at least 0.01 ms.sup.-1,
or at least 0.05 ms.sup.-1.
[0080] When the air flow rate inhaled by the user through the
apparatus is 1.3 L min.sup.-1, the maximum magnitude of velocity of
air in the vaporizer element region may be at most 1.9 ms.sup.-1,
at most 1.8 ms.sup.-1, at most 1.7 ms.sup.-1, at most 1.6
ms.sup.-1, at most 1.5 ms.sup.-1, at most 1.4 ms.sup.-1, at most
1.3 ms.sup.-1 or at most 1.2 ms.sup.-1.
[0081] The air inlet, flow passage, outlet and the vaporization
chamber may be configured so that, when the air flow rate inhaled
by the user through the apparatus is 2.0 L min.sup.-1, the maximum
magnitude of velocity of air in the vaporizer element region is in
the range 0-2.0 ms.sup.-1.
[0082] When the air flow rate inhaled by the user through the
apparatus is 2.0 L min.sup.-1, the maximum magnitude of velocity of
air in the vaporizer element region may be at least 0.001
ms.sup.-1, or at least 0.005 ms.sup.-1, or at least 0.01 ms.sup.-1,
or at least 0.05 ms.sup.-1.
[0083] When the air flow rate inhaled by the user through the
apparatus is 2.0 L min.sup.-1, the maximum magnitude of velocity of
air in the vaporizer element region may be at most 1.9 ms.sup.-1,
at most 1.8 ms.sup.-1, at most 1.7 ms.sup.-1, at most 1.6
ms.sup.-1, at most 1.5 ms.sup.-1, at most 1.4 ms.sup.-1, at most
1.3 ms.sup.-1 or at most 1.2 ms.sup.-1.
[0084] It is considered that configuring the apparatus in a manner
to permit such control of velocity of the airflow at the vaporizer
permits the generation of aerosols with particularly advantageous
particle size characteristics, including Dv50 values.
[0085] Additionally, or alternatively, it is relevant to consider
the turbulence intensity in the vaporizer chamber in view of the
effect of turbulence on the particle size of the generated aerosol.
For example, the air inlet, flow passage, outlet and the
vaporization chamber may be configured so that, when the air flow
rate inhaled by the user through the apparatus is 1.3 L min.sup.-1,
the turbulence intensity in the vaporizer element region is not
more than 1%.
[0086] When the air flow rate inhaled by the user through the
apparatus is 1.3 L min.sup.-1, the turbulence intensity in the
vaporizer element region may be not more than 0.95%, not more than
0.9%, not more than 0.85%, not more than 0.8%, not more than 0.75%,
not more than 0.7%, not more than 0.65% or not more than 0.6%.
[0087] It is considered that configuring the apparatus in a manner
to permit such control of the turbulence intensity in the vaporizer
element region permits the generation of aerosols with particularly
advantageous particle size characteristics, including Dv50
values.
[0088] Following detailed investigations, the inventors consider,
without wishing to be bound by theory, that the particle size
characteristics of the generated aerosol may be determined by the
cooling rate experienced by the vapor after emission from the
vaporizer element (e.g., wick). In particular, it appears that
imposing a relatively slow cooling rate on the vapor has the effect
of generating aerosols with a relatively large particle size. The
parameters discussed above (velocity and turbulence intensity) are
considered to be mechanisms for implementing a particular cooling
dynamic to the vapor.
[0089] More generally, it is considered that the air inlet, flow
passage, outlet and the vaporization chamber may be configured so
that a desired cooling rate is imposed on the vapor. The particular
cooling rate to be used depends of course on the nature of the
aerosol precursor and other conditions. However, for a particular
aerosol precursor it is possible to define a set of testing
conditions in order to define the cooling rate, and by extension
this imposes limitations on the configuration of the apparatus to
permit such cooling rates as are shown to result in advantageous
aerosols. Accordingly, the air inlet, flow passage, outlet and the
vaporization chamber may be configured so that the cooling rate of
the vapor is such that the time taken to cool to 50.degree. C. is
not less than 16 ms, when tested according to the following
protocol. The aerosol precursor is an e-liquid consisting of 1.6%
freebase nicotine and the remainder a 65:35 propylene glycol and
vegetable glycerin mixture, the e-liquid having a boiling point of
209.degree. C. Air is drawn into the air inlet at a temperature of
25.degree. C. The vaporizer is operated to release a vapor of total
particulate mass 5 mg over a 3 second duration from the vaporizer
element surface in an air flow rate between the air inlet and
outlet of 1.3 L min.sup.-1.
[0090] Additionally, or alternatively, the air inlet, flow passage,
outlet and the vaporization chamber may be configured so that the
cooling rate of the vapor is such that the time taken to cool to
50.degree. C. is not less than 16 ms, when tested according to the
following protocol. The aerosol precursor is an e-liquid consisting
of 1.6% freebase nicotine and the remainder a 65:35 propylene
glycol and vegetable glycerin mixture, the e-liquid having a
boiling point of 209.degree. C. Air is drawn into the air inlet at
a temperature of 25.degree. C. The vaporizer is operated to release
a vapor of total particulate mass 5 mg over a 3 second duration
from the vaporizer element surface in an air flow rate between the
air inlet and outlet of 2.0 L min.sup.-1.
[0091] Cooling of the vapor such that the time taken to cool to
50.degree. C. is not less than 16 ms corresponds to an equivalent
linear cooling rate of not more than 10.degree. C./ms.
[0092] The equivalent linear cooling rate of the vapor to
50.degree. C. may be not more than 9.degree. C./ms, not more than
8.degree. C./ms, not more than 7.degree. C./ms, not more than
6.degree. C./ms or not more than 5.degree. C./ms.
[0093] Cooling of the vapor such that the time taken to cool to
50.degree. C. is not less than 32 ms corresponds to an equivalent
linear cooling rate of not more than 5.degree. C./ms.
[0094] The testing protocol set out above considers the cooling of
the vapor (and subsequent aerosol) to a temperature of 50.degree.
C. This is a temperature which can be considered to be suitable for
an aerosol to exit the apparatus for inhalation by a user without
causing significant discomfort. It is also possible to consider
cooling of the vapor (and subsequent aerosol) to a temperature of
75.degree. C. Although this temperature is possibly too high for
comfortable inhalation, it is considered that the particle size
characteristics of the aerosol are substantially settled by the
time the aerosol cools to this temperature (and they may be settled
at still higher temperature).
[0095] Accordingly, the air inlet, flow passage, outlet and the
vaporization chamber may be configured so that the cooling rate of
the vapor is such that the time taken to cool to 75.degree. C. is
not less than 4.5 ms, when tested according to the following
protocol. The aerosol precursor is an e-liquid consisting of 1.6%
freebase nicotine and the remainder a 65:35 propylene glycol and
vegetable glycerin mixture, the e-liquid having a boiling point of
209.degree. C. Air is drawn into the air inlet at a temperature of
25.degree. C. The vaporizer is operated to release a vapor of total
particulate mass 5 mg over a 3 second duration from the vaporizer
element surface in an air flow rate between the air inlet and
outlet of 1.3 L min.sup.-1.
[0096] Additionally, or alternatively, the air inlet, flow passage,
outlet and the vaporization chamber may be configured so that the
cooling rate of the vapor is such that the time taken to cool to
75.degree. C. is not less than 4.5 ms, when tested according to the
following protocol. The aerosol precursor is an e-liquid consisting
of 1.6% freebase nicotine and the remainder a 65:35 propylene
glycol and vegetable glycerin mixture, the e-liquid having a
boiling point of 209.degree. C. Air is drawn into the air inlet at
a temperature of 25.degree. C. The vaporizer is operated to release
a vapor of total particulate mass 5 mg over a 3 second duration
from the vaporizer element surface in an air flow rate between the
air inlet and outlet of 2.0 L min.sup.-1.
[0097] Cooling of the vapor such that the time taken to cool to
75.degree. C. is not less than 4.5 ms corresponds to an equivalent
linear cooling rate of not more than 30.degree. C./ms.
[0098] The equivalent linear cooling rate of the vapor to
75.degree. C. may be not more than 29.degree. C./ms, not more than
28.degree. C./ms, not more than 27.degree. C./ms, not more than
26.degree. C./ms, not more than 25.degree. C./ms, not more than
24.degree. C./ms, not more than 23.degree. C./ms, not more than
22.degree. C./ms, not more than 21.degree. C./ms, not more than
20.degree. C./ms, not more than 19.degree. C./ms, not more than
18.degree. C./ms, not more than 17.degree. C./ms, not more than
16.degree. C./ms, not more than 15.degree. C./ms, not more than
14.degree. C./ms, not more than 13.degree. C./ms, not more than
12.degree. C./ms, not more than 11.degree. C./ms or not more than
10.degree. C./ms.
[0099] Cooling of the vapor such that the time taken to cool to
75.degree. C. is not less than 13 ms corresponds to an equivalent
linear cooling rate of not more than 10.degree. C./ms.
[0100] It is considered that configuring the apparatus in a manner
to permit such control of the cooling rate of the vapor permits the
generation of aerosols with particularly advantageous particle size
characteristics, including Dv50 values.
Development B
[0101] For a smoking substitute system, it is desirable to deliver
nicotine into the user's lungs, where it can be absorbed into the
bloodstream. However, the present disclosure is based in part on a
realization that some prior art smoking substitute systems, such
delivery of nicotine is not efficient. In some prior art systems,
the aerosol droplets have a size distribution that is not suitable
for delivering nicotine to the lungs. Aerosol droplets of a large
particle size tend to be deposited in the mouth and/or upper
respiratory tract. Aerosol particles of a small (e.g., sub-micron)
particle size can be inhaled into the lungs but may be exhaled
without delivering nicotine to the lungs. As a result, the user
would require drawing a longer puff, more puffs, or vaporizing
e-liquid with a higher nicotine concentration in order to achieve
the desired experience.
[0102] Accordingly, there is a need for improvement in the delivery
of nicotine to a user in the context of a smoking substitute
system.
[0103] The present disclosure (Development B) has been devised in
the light of the above considerations.
[0104] In a general aspect of Development B, the present disclosure
relates to a smoking substitute apparatus with electrical
connection between at least one electrical contact and a heater,
the electrical connection being advantageously routed in order to
take account of the construction of the air flow channel upstream
of the aerosol generator.
[0105] According to a first preferred aspect of Development B there
is provided a smoking substitute apparatus comprising: a housing
having a longitudinal axis, the housing having a first end and a
second end; an air inlet at the first end of the housing; an air
outlet at the second end of the housing; an aerosol generation
chamber comprising an aerosol generator for generating an aerosol
from an aerosol precursor; an air flow channel extending between
the air inlet and the air outlet and passing through the aerosol
generation chamber; a plenum chamber positioned in the air flow
channel upstream of the aerosol generation chamber, the plenum
chamber being configured to condition, in use, the air flow before
reaching the aerosol generator in the aerosol generation chamber;
at least one electrical contact at the first end of the housing; at
least one electrical conductor electrically connecting the at least
one electrical contact to the aerosol generator; wherein at least a
portion of the at least one electrical conductor is positioned
along a sidewall of the plenum chamber.
[0106] An advantage of positioning the electrical conductors along
the sidewall is reducing, or minimizing, disturbance to the air
flow through the air flow channel. The air flow may be less
turbulent in the aerosol generation chamber. This can help to
increase particle size of particles formed in the aerosol
generation chamber. Another advantage of positioning the electrical
conductors along the sidewall is reducing, or minimizing, stress on
the electrical conductors. The electrical conductors are supported
and should be less likely to suffer damage from air flow through
the air flow channel.
[0107] Optionally, the at least one electrical conductor is
positioned along the sidewall of the air flow channel along its
length.
[0108] Optionally, the at least one electrical conductor follows a
non-linear path between the at least one electrical contact and the
aerosol generator. While this increases the length of the
electrical conductor, it can allow a routing which can reduce
damage to the electrical conductor.
[0109] Optionally, the plenum chamber has a length along the
longitudinal axis of at least 5 mm.
[0110] Optionally, the smoking substitute apparatus comprises a
flow modifying device extending across the air flow channel at a
position between the air inlet and the aerosol generator and
wherein the at least one electrical conductor passes through the
flow modifying device.
[0111] Optionally, the at least one electrical conductor is bonded
to an inner surface of the sidewall of the plenum chamber.
[0112] Optionally, there is a first electrical contact and a second
electrical contact, a first electrical conductor electrically
connecting the first electrical contact to the aerosol generator
and a second electrical conductor electrically connecting the
second electrical contact to the aerosol generator, and wherein the
first electrical conductor and the second electrical conductor are
positioned on opposing parts of the sidewall, or on opposing
sidewalls, of the air flow channel. This can improve electrical
isolation of the electrical conductors.
[0113] According to a second preferred aspect of Development B
there is provided a smoking substitute apparatus comprising: a
housing having a longitudinal axis, the housing having a first end
and a second end; an air inlet at the first end of the housing; an
air outlet at the second end of the housing; an aerosol generation
chamber comprising an aerosol generator for generating an aerosol
from an aerosol precursor; an air flow channel extending between
the air inlet and the air outlet and passing through the aerosol
generation chamber; a plenum chamber positioned in the air flow
channel upstream of the aerosol generation chamber, the plenum
chamber being configured to condition, in use, the air flow before
reaching the aerosol generator in the aerosol generation chamber;
at least one electrical contact at the first end of the housing; at
least one electrical conductor electrically connecting the at least
one electrical contact to the aerosol generator; wherein at least a
portion of the at least one electrical conductor extends directly
through a void in the air flow channel, out of contact with a
sidewall of the plenum chamber.
[0114] An advantage of routing the electrical conductors in this
way is a more physically direct, i.e., shortest, path. This
reduces, or minimizes, energy losses due to electrical resistance
of the conductors. This can improve battery life and allow a longer
operational period between charges.
[0115] Optionally, a major portion of the at least one electrical
conductor follows a path which is parallel to the longitudinal
axis.
[0116] Optionally, the plenum chamber has a length along the
longitudinal axis of at least 5 mm.
[0117] Optionally, the smoking substitute apparatus comprises a
flow modifying device extending across the air flow channel at a
position between the air inlet and the aerosol generator, wherein
the at least one electrical conductor passes through the flow
modifying device, the flow modifying device providing support to
the at least one electrical conductor. This can have an advantage
of supporting the electrical conductor without needing to provide a
dedicated structural support.
[0118] Another aspect of Development B provides a smoking
substitute system comprising: a main body having one or more
electrical contacts connected to, or connectable to, a power source
in the main body; and a smoking substitute apparatus according to
the first aspect of Development B or according to the second aspect
of Development B.
Development C
[0119] For a smoking substitute system, it is desirable to deliver
nicotine into the user's lungs, where it can be absorbed into the
bloodstream. However, the present disclosure is based in part on a
realization that some prior art smoking substitute systems, such
delivery of nicotine is not efficient. In some prior art systems,
the aerosol droplets have a size distribution that is not suitable
for delivering nicotine to the lungs. Aerosol droplets of a large
particle size tend to be deposited in the mouth and/or upper
respiratory tract. Aerosol particles of a small (e.g., sub-micron)
particle size can be inhaled into the lungs but may be exhaled
without delivering nicotine to the lungs. As a result, the user
would require drawing a longer puff, more puffs, or vaporizing
e-liquid with a higher nicotine concentration in order to achieve
the desired experience.
[0120] Accordingly, there is a need for improvement in the delivery
of nicotine to a user in the context of a smoking substitute
system.
[0121] The present disclosure (Development C) has been devised in
the light of the above considerations.
[0122] In a general aspect of Development C, the present disclosure
relates to a smoking substitute apparatus including a configurable
plenum chamber to promote a laminar property to air flow presented
to an aerosol generator.
[0123] According to a first preferred aspect of Development C there
is provided a smoking substitute apparatus comprising: [0124] an
air inlet and an air outlet, wherein the air inlet is in fluid
communication with the air outlet through an air flow passage;
[0125] an aerosol generator, located in the air flow passage and
configured to generate an aerosol from an aerosol precursor; and
[0126] a plenum chamber, disposed in the air flow passage upstream
of the aerosol generator and being configurable to include at least
one flow modifying device extending across the air flow passage at
a position between the air inlet and the aerosol generator; [0127]
wherein the flow modifying device is configured affect a
characteristic of the air flow to the aerosol generator, the
position of the flow modifying device in the plenum chamber being
selectable between at least two positions to affect the
characteristic of the air flow presented to the aerosol
generator.
[0128] Advantageously, this such a smoking substitute apparatus
permits the modification of air flow through the apparatus in a
manner which controls the speed and shape of air flow entering the
aerosol generator. Correspondingly, this can facilitate the control
of aerosolized particles of the aerosol precursor.
[0129] The flow modifying device may be configured to promote a
laminar property to the air flow to the aerosol generator.
[0130] The plenum chamber may be contained within a flow
conditioning module, separable from the air outlet. In some
examples, the flow conditioning module may be separable from the
aerosol generator. In other examples, the flow conditioning module
may be separable from a chimney which fluidly connects the aerosol
generator to the air outlet. An end user can therefore interchange
the flow conditioning module with other flow conditioning modules
to achieve a desired air flow characteristic.
[0131] The plenum chamber may be configurable to include a
plurality of flow modifying devices. The granularity with which the
air flow can be modified is thereby increased, and so the control
over particle size is enhanced.
[0132] The plenum chamber may be configurable to include one or
more spacers within the plenum chamber, the one or more spacers may
be configured to assist in defining the position of the flow
modifying device(s) in the plenum chamber. This increases the
flexibility with which the flow modifying device(s) can be
installed within the plenum chamber. There may be a plurality of
spacers, which are configured to be interchangeable within the
plenum chamber, so as to allow the repositioning of the flow
modifying device(s) within the plenum chamber. Two or more of the
plurality of spacers may have differing geometries.
[0133] The plenum chamber may be configurable to include a
plurality of flow modifying devices which are interchangeable
within the plenum chamber, each flow modifying device affecting the
characteristic of the air flow differently. Where the plenum
chamber is configurable to include a plurality of flow modifying
devices, and a plurality of spacers, the spacers and the plurality
of flow modifying devices may be interchangeable within the plenum
chamber.
[0134] The flow modifying devices may be meshes.
[0135] The plenum chamber may include one or more of the flow
modifying devices discussed previously. The plenum chamber may
include one or more of the spacers discussed previously.
[0136] The disclosure includes the combination of the developments,
aspects and preferred features described except where such a
combination is clearly impermissible or expressly avoided.
BRIEF DESCRIPTION OF THE FIGURES
[0137] So that the disclosure may be understood, and so that
further aspects and features thereof may be appreciated,
embodiments illustrating the principles of the disclosure will now
be discussed in further detail with reference to the accompanying
figures, in which:
[0138] FIG. 1 illustrates a set of rectangular tubes for use in
experiments to assess the effect of flow and cooling conditions at
the wick on aerosol properties. Each tube has the same depth and
length but different width.
[0139] FIG. 2 shows a schematic perspective longitudinal cross
sectional view of an example rectangular tube with a wick and
heater coil installed.
[0140] FIG. 3 shows a schematic transverse cross sectional view an
example rectangular tube with a wick and heater coil installed. In
this example, the internal width of the tube is 12 mm.
[0141] FIGS. 4A-4D show air flow streamlines in the four devices
used in a turbulence study.
[0142] FIG. 5 shows the experimental set up to investigate the
influence of inflow air temperature on aerosol particle size, in
order to investigate the effect of vapor cooling rate on aerosol
generation.
[0143] FIG. 6 shows a schematic longitudinal cross sectional view
of a first smoking substitute apparatus (pod 1) used to assess
influence of inflow air temperature on aerosol particle size.
[0144] FIG. 7 shows a schematic longitudinal cross sectional view
of a second smoking substitute apparatus (pod 2) used to assess
influence of inflow air temperature on aerosol particle size.
[0145] FIG. 8A shows a schematic longitudinal cross sectional view
of a third smoking substitute apparatus (pod 3) used to assess
influence of inflow air temperature on aerosol particle size.
[0146] FIG. 8B shows a schematic longitudinal cross sectional view
of the same third smoking substitute apparatus (pod 3) in a
direction orthogonal to the view taken in FIG. 8A.
[0147] FIG. 9 shows a plot of aerosol particle size (Dv50)
experimental results against calculated air velocity.
[0148] FIG. 10 shows a plot of aerosol particle size (Dv50)
experimental results against the flow rate through the apparatus
for a calculated air velocity of 1 m/s.
[0149] FIG. 11 shows a plot of aerosol particle size (Dv50)
experimental results against the average magnitude of the velocity
in the vaporizer surface region, as obtained from CFD
modelling.
[0150] FIG. 12 shows a plot of aerosol particle size (Dv50)
experimental results against the maximum magnitude of the velocity
in the vaporizer surface region, as obtained from CFD
modelling.
[0151] FIG. 13 shows a plot of aerosol particle size (Dv50)
experimental results against the turbulence intensity.
[0152] FIG. 14 shows a plot of aerosol particle size (Dv50)
experimental results dependent on the temperature of the air and
the heating state of the apparatus.
[0153] FIG. 15 shows a plot of aerosol particle size (Dv50)
experimental results against vapor cooling rate to 50.degree.
C.
[0154] FIG. 16 shows a plot of aerosol particle size (Dv50)
experimental results against vapor cooling rate to 75.degree.
C.
[0155] FIG. 17 is a schematic front view of a smoking substitute
system, according to a reference arrangement, in an engaged
position;
[0156] FIG. 18 is a schematic front view of the smoking substitute
system of the reference arrangement in a disengaged position;
[0157] FIG. 19 is a schematic longitudinal cross sectional view of
a smoking substitute apparatus of the reference arrangement;
and
[0158] FIG. 20 is an enlarged schematic cross sectional view of
part of the air passage and vaporization chamber of the reference
arrangement;
[0159] FIG. 21 is a schematic view cross sectional view of a
smoking substitute system, according to a first embodiment of
Development A; and
[0160] FIG. 22 is a schematic view cross sectional view of a
smoking substitute system, according to a second embodiment of
Development A.
[0161] FIG. 23 is a cross sectional view of a smoking substitute
apparatus of an embodiment of Development B;
[0162] FIG. 24 is a cross sectional view of a smoking substitute
apparatus another embodiment of Development B.
[0163] FIG. 25 is a cross sectional view of a smoking substitute
apparatus according to the first embodiment of Development C;
and
[0164] FIGS. 26A-26D are cross sectional views of a flow
conditioning module in various configurations.
DETAILED DESCRIPTION OF THE DISCLOSURE
[0165] Further background to the present disclosure and further
aspects and embodiments of the present disclosure will now be
discussed with reference to the accompanying figures. Further
aspects and embodiments will be apparent to those skilled in the
art. The contents of all documents mentioned in this text are
incorporated herein by reference in their entirety.
[0166] FIGS. 17 and 18 illustrate a smoking substitute system in
the form of an e-cigarette system 110. The system 110 comprises a
main body 120 of the system 110, and a smoking substitute apparatus
in the form of an e-cigarette consumable (or "pod") 150. In the
illustrated embodiment the consumable 150 (sometimes referred to
herein as a smoking substitute apparatus) is removable from the
main body 120, so as to be a replaceable component of the system
110. The e-cigarette system 110 is a closed system in the sense
that it is not intended that the consumable should be refillable
with e-liquid by a user.
[0167] As is apparent from FIGS. 17 and 18, the consumable 150 is
configured to engage the main body 120. FIG. 17 shows the main body
120 and the consumable 150 in an engaged state, whilst FIG. 18
shows the main body 120 and the consumable 150 in a disengaged
state. When engaged, a portion of the consumable 150 is received in
a cavity of corresponding shape in the main body 120 and is
retained in the engaged position by way of a snap-engagement
mechanism. In other embodiments, the main body 120 and consumable
150 may be engaged by screwing one into (or onto) the other, or
through a bayonet fitting, or by way of an interference fit.
[0168] The system 110 is configured to vaporize an aerosol
precursor, which in the illustrated embodiment is in the form of a
nicotine-based e-liquid 160. The e-liquid 160 comprises nicotine
and a base liquid including propylene glycol and/or vegetable
glycerin. In the present embodiment, the e-liquid 160 is flavored
by a flavorant. In other embodiments, the e-liquid 160 may be
flavorless and thus may not include any added flavorant.
[0169] FIG. 19 shows a schematic longitudinal cross sectional view
of the smoking substitute apparatus forming part of the smoking
substitute system shown in FIGS. 17 and 18. In FIG. 19, the
e-liquid 160 is stored within a reservoir in the form of a tank 152
that forms part of the consumable 150. In the illustrated
arrangement, the consumable 150 is a "single-use" consumable 150.
That is, upon exhausting the e-liquid 160 in the tank 152, the
intention is that the user disposes of the entire consumable 150.
The term "single-use" does not necessarily mean the consumable is
designed to be disposed of after a single smoking session. Rather,
it defines the consumable 150 is not arranged to be refilled after
the e-liquid contained in the tank 152 is depleted. The tank may
include a vent (not shown) to allow ingress of air to replace
e-liquid that has been used from the tank. The consumable 150
preferably includes a window 158 (see FIGS. 17 and 18), so that the
amount of e-liquid in the tank 152 can be visually assessed. The
main body 120 includes a slot 157 so that the window 158 of the
consumable 150 can be seen whilst the rest of the tank 152 is
obscured from view when the consumable 150 is received in the
cavity of the main body 120. The consumable 150 may be referred to
as a "clearomizer" when it includes a window 158, or a "cartomizer"
when it does not.
[0170] In other embodiments, the e-liquid (i.e., aerosol precursor)
may be the only part of the system that is truly "single-use". That
is, the tank may be refillable with e-liquid or the e-liquid may be
stored in a non-consumable component of the system. For example, in
such other embodiments, the e-liquid may be stored in a tank
located in the main body or stored in another component that is
itself not single-use (e.g., a refillable cartomizer).
[0171] The external wall of tank 152 is provided by a casing of the
consumable 150. The tank 152 annularly surrounds, and thus defines
a portion of, a passage 170 that extends between a vaporizer inlet
172 and an outlet 174 at opposing ends of the consumable 150. In
this respect, the passage 170 comprises an upstream end at the end
of the consumable 150 that engages with the main body 120, and a
downstream end at an opposing end of the consumable 150 that
comprises a mouthpiece 154 of the system 110.
[0172] When the consumable 150 is received in the cavity of the
main body 120 as shown in FIG. 19, a plurality of device air inlets
176 are formed at the boundary between the casing of the consumable
and the casing of the main body. The device air inlets 176 are in
fluid communication with the vaporizer inlet 172 through an inlet
flow channel 178 formed in the cavity of the main body which is of
corresponding shape to receive a part of the consumable 150. Air
from outside of the system 110 can therefore be drawn into the
passage 170 through the device air inlets 176 and the inlet flow
channels 178.
[0173] When the consumable 150 is engaged with the main body 120, a
user can inhale (i.e., take a puff) via the mouthpiece 154 so as to
draw air through the passage 170, and so as to form an airflow
(indicated by the dashed arrows in FIG. 3) in a direction from the
vaporizer inlet 172 to the outlet 174. Although not illustrated,
the passage 170 may be partially defined by a tube (e.g., a metal
tube) extending through the consumable 150. In FIG. 19, for
simplicity, the passage 170 is shown with a substantially circular
cross-sectional profile with a constant diameter along its length.
In other embodiments, the passage may have other cross-sectional
profiles, such as oval shaped or polygonal shaped profiles.
Further, in other embodiments, the cross sectional profile and the
diameter (or hydraulic diameter) of the passage may vary along its
longitudinal axis.
[0174] The smoking substitute system 110 is configured to vaporize
the e-liquid 160 for inhalation by a user. To provide this
operability, the consumable 150 comprises a heater having a porous
wick 162 and a resistive heating element in the form of a heating
filament 164 that is helically wound (in the form of a coil) around
a portion of the porous wick 162. The porous wick 162 extends
across the passage 170 (i.e., transverse to a longitudinal axis of
the passage 170 and thus also transverse to the air flow along the
passage 170 during use) and opposing ends of the wick 162 extend
into the tank 152 (so as to be immersed in the e-liquid 160). In
this way, e-liquid 160 contained in the tank 152 is conveyed from
the opposing ends of the porous wick 162 to a central portion of
the porous wick 162 so as to be exposed to the airflow in the
passage 170.
[0175] The helical filament 164 is wound about the exposed central
portion of the porous wick 162 and is electrically connected to an
electrical interface in the form of electrical contacts 156 mounted
at the end of the consumable that is proximate the main body 120
(when the consumable and the main body are engaged). When the
consumable 150 is engaged with the main body 120, electrical
contacts 156 make contact with corresponding electrical contacts
(not shown) of the main body 120. The main body electrical contacts
are electrically connectable to a power source (not shown) of the
main body 120, such that (in the engaged position) the filament 164
is electrically connectable to the power source. In this way, power
can be supplied by the main body 120 to the filament 164 in order
to heat the filament 164. This heats the porous wick 162 which
causes e-liquid 160 conveyed by the porous wick 162 to vaporize and
thus to be released from the porous wick 162. The vaporized
e-liquid becomes entrained in the airflow and, as it cools in the
airflow (between the heated wick and the outlet 174 of the passage
170), condenses to form an aerosol. This aerosol is then inhaled,
via the mouthpiece 154, by a user of the system 110. As e-liquid is
lost from the heated portion of the wick, further e-liquid is drawn
along the wick from the tank to replace the e-liquid lost from the
heated portion of the wick.
[0176] The filament 164 and the exposed central portion of the
porous wick 162 are positioned across the passage 170. More
specifically, the part of passage that contains the filament 164
and the exposed portion of the porous wick 162 forms a vaporization
chamber. In the illustrated example, the vaporization chamber has
the same cross-sectional diameter as the passage 170. However, in
other embodiments the vaporization chamber may have a different
cross sectional profile as the passage 170. For example, the
vaporization chamber may have a larger cross sectional diameter
than at least some of the downstream part of the passage 170 so as
to enable a longer residence time for the air inside the
vaporization chamber.
[0177] FIG. 20 illustrates in more detail the vaporization chamber
and therefore the region of the consumable 150 around the wick 162
and filament 164. The helical filament 164 is wound around a
central portion of the porous wick 162. The porous wick extends
across passage 170. E-liquid 160 contained within the tank 152 is
conveyed as illustrated schematically by arrows 401, i.e., from the
tank and towards the central portion of the porous wick 162.
[0178] When the user inhales, air is drawn from through the inlets
176 shown in FIG. 19, along inlet flow channel 178 to vaporization
chamber inlet 172 and into the vaporization chamber containing
porous wick 162. The porous wick 162 extends substantially
transverse to the airflow direction. The airflow passes around the
porous wick, at least a portion of the airflow substantially
following the surface of the porous wick 162. In examples where the
porous wick has a cylindrical cross-sectional profile, the airflow
may follow a curved path around an outer periphery of the porous
wick 162.
[0179] At substantially the same time as the airflow passes around
the porous wick 162, the filament 164 is heated so as to vaporize
the e-liquid which has been wicked into the porous wick. The
airflow passing around the porous wick 162 picks up this vaporized
e-liquid, and the vapor-containing airflow is drawn in direction
403 further down passage 170.
[0180] The power source of the main body 120 may be in the form of
a battery (e.g., a rechargeable battery such as a lithium-ion
battery). The main body 120 may comprise a connector in the form
of, e.g., a USB port for recharging this battery. The main body 120
may also comprise a controller that controls the supply of power
from the power source to the main body electrical contacts (and
thus to the filament 164). That is, the controller may be
configured to control a voltage applied across the main body
electrical contacts, and thus the voltage applied across the
filament 164. In this way, the filament 164 may only be heated
under certain conditions (e.g., during a puff and/or only when the
system is in an active state). In this respect, the main body 120
may include a puff sensor (not shown) that is configured to detect
a puff (i.e., inhalation). The puff sensor may be operatively
connected to the controller so as to be able to provide a signal,
to the controller, which is indicative of a puff state (i.e.,
puffing or not puffing). The puff sensor may, for example, be in
the form of a pressure sensor or an acoustic sensor.
[0181] Although not shown, the main body 120 and consumable 150 may
comprise a further interface which may, for example, be in the form
of an RFID reader, a barcode or QR code reader. This interface may
be able to identify a characteristic (e.g., a type) of a consumable
150 engaged with the main body 120. In this respect, the consumable
150 may include any one or more of an RFID chip, a barcode or QR
code, or memory within which is an identifier and which can be
interrogated via the interface.
Development A
[0182] FIG. 21 shows a first embodiment of a smoking substitute
system in the form of an e-cigarette system a510. The system
comprises a main body a520 of the system a510, and a smoking
substitute apparatus in the form of an e-cigarette consumable (or
"pod") a550. The main body a520 of the system a510 is similar to
the main body 120 of the system 110 described above and shown in
FIGS. 17 and 18. The smoking substitute apparatus a550 is similar
to the smoking substitute apparatus 150 described above and shown
in FIGS. 17-20. Similar to the reference arrangement, the
consumable a550 (sometimes referred to herein as a smoking
substitute apparatus) is removable from the main body a520, so as
to be a replaceable component of the system a510. The consumable
a550 is configured to engage the main body a520. FIG. 21 shows the
main body a520 and the consumable a550 in an engaged state. When
engaged, a portion of the consumable a550 is received in a cavity
of corresponding shape in the main body a520 and is retained in the
engaged position by way of a snap-engagement mechanism. In other
embodiments, the main body a520 and consumable a550 may be engaged
by screwing one into (or onto) the other, or through a bayonet
fitting, or by way of an interference fit.
[0183] The consumable a550 has an air inlet a572. One difference,
compared to the reference arrangement, is that the air inlet a572
of the consumable a550 receives a supply of air via the main body
a520. The main body a520 has an air inlet a522. In FIG. 21 the air
inlet a522 is at a distal end a532 of the main body a520, furthest
from the end a531 of the main body which engages with the
consumable a550. The main body comprises a plenum chamber a524. The
plenum chamber a524 is located immediately upstream of the air
inlet a572, when the consumable a550 is coupled to, or engaged
with, the main body a520. The plenum chamber a524 is a region which
allows incoming air to settle before entering the air inlet a572 of
the consumable a550. The plenum chamber a524 may comprise a void
which extends across all, or a part of, the main body a520. FIG. 21
shows an airflow path a527. Air enters the air inlet a522 of the
main body a520 and then flows around, or over, components of the
main body such as a battery and a controller. Air then reaches the
plenum chamber a524. Air settles in the plenum chamber a524 before
entering the air inlet a572 of the consumable a550. The air inlet
a572 leads to the vaporization chamber of the consumable a550.
Components of the consumable a550 may be similar to the ones
described above for consumable a550. They include a wick a562, a
heater a564, a tank a552 containing e-liquid a560 and an airflow
passage a570. The consumable a550 has an outlet a574 at the
downstream end a554.
[0184] The air inlet a572 of the consumable a550 may have an
enlarged cross-section compared to the reference arrangement. For
example, a cross-sectional area of the inlet a572 may be at least
70%, optionally at least 80%, optionally at least 90% of an overall
cross-sectional area of the consumable a550. The air flow channel
leading to the wick a572 may be inwardly tapered between the air
inlet a572 and the wick a572.
[0185] FIG. 21 shows electrical connection between the main body
a520 and the consumable a550. Electrical contacts a556 are provided
on a sidewall of a housing of the consumable a550. Electrical
contacts a526 are provided on a sidewall of a housing of the main
body a520. When the consumable a550 is engaged with the main body
a520, the electrical contacts a556 make physical and contact with
corresponding electrical contacts a526 of the main body a120. This
provides a path for electrical current between a battery in the
main body a520 and the heater a564 in the consumable a550. Location
of the electrical contacts on the sidewall can allow a larger
unobstructed air inlet a572.
[0186] In other embodiments the electrical contacts 556 may be
located on an end face of the consumable a550. The term "end face"
means a surface of the consumable which faces the main body. The
end face may comprise an annular shaped region of housing
surrounding the inlet a172. The end face may be orthogonal to the
longitudinal axis of the consumable. For example, the electrical
contacts a556 may be provided on an end face in a location beyond a
perimeter of the air inlet a572. Stated another way, when the
consumable a550 is viewed in plan (i.e., end on) the electrical
contacts a556 do not overlap the air inlet a172.
[0187] FIG. 22 shows a second embodiment of a smoking substitute
system in the form of an e-cigarette system a610. The system
comprises a main body a620 and a smoking substitute apparatus in
the form of an e-cigarette consumable (or "pod") a550. The
consumable a550 may be the same as shown in FIG. 21. The main body
a620 couples to the consumable a550 as described above. The main
body a620 comprises a plenum chamber a524 as described above.
[0188] The main body a620 has an air inlet a622 located adjacent
the plenum chamber a524. In FIG. 22 the air inlet a622 is shown in
a sidewall of a housing of the main body a620. FIG. 22 shows an
airflow path a627. Air enters the air inlet a622 of the main body
a620 and flows into an upstream end of the plenum chamber a524. Air
settles in the plenum chamber a524 before entering the air inlet
a572 of the consumable a550.
[0189] It will be understood that in other embodiments, not shown,
the air inlet to the main body may be located at a different
location on the main body, such as a location which is axially
offset, along the longitudinal axis of the main body, between the
plenum chamber a524 and the distal end a532 of the main body
a520.
[0190] The experimental work reported below is relevant to the
embodiments disclosed above in view of the effect shown by which
the air flow conditions at the wick have an influence on the
particle size of the generated aerosol. The provision of a plenum
chamber upstream of the wick in the smoking substitute system
affects the air flow conditions at the wick.
Development B
[0191] FIG. 23 shows a consumable b550 according to an embodiment.
The consumable b550 has many features which are the same as, or
similar to, the reference arrangement shown in FIGS. 17 to 20. The
consumable b550 comprises a housing with a longitudinal axis b101.
The housing has a first end b551 and a second end b552. An air
inlet b172 to the housing is formed in end face b500 at the first
end b551 of the housing. An air outlet, or mouthpiece, b174 is
formed at the second end b552 of the housing. The internal
components of the consumable b550 are similar to the ones
previously described. The consumable has a vaporization chamber
with a heater b164 and a wick b162. The heater b164 generates an
aerosol. An air flow channel extends between the air inlet b172 and
the air outlet b174 and passes through the vaporization
chamber.
[0192] For completeness, FIG. 23 shows a complete air flow path. As
shown in FIGS. 17 and 18, consumable 150, b550 can engage with a
main body 120. Air inlets b176 allow air to enter an air flow
channel between the consumable 150, b550 and the main body 120. Air
follows an axial path along the outside of the housing, before
passing radially across the end face b500 at the first end b551 of
the housing and entering the air inlet b172 to the interior volume
of the housing.
[0193] At least one electrical contact b156 is provided at the
first end b551 of the housing. In FIG. 23, there is a pair of
electrical contacts b156. The electrical contracts are provided at
a central position, close to the longitudinal axis b101. As
described above, the electrical contacts b156 make contact with
corresponding electrical contacts (not shown) of the main body 120.
An electrical conductor b501 electrically connects an electrical
contact b156 with the heater b164. In FIG. 23 there are two
electrical conductors: a first electrical conductor b501 between a
first of the electrical contacts b156 and a first end of the heater
b164; and a second electrical conductor b501 between a second of
the electrical contacts b156 and a second end of the heater b164.
In FIG. 23, the routing of each electrical conductor b501 is along
a sidewall of the air flow channel. Starting at a first of the
electrical contacts b156 at the first end b551, the conductor b501
is first routed radially along an edge of the air flow channel to
an axial wall of the air flow channel. Then, the conductor is
routed axially along the interior wall of the air flow channel. The
air flow channel steps radially inwards near to the wick b162. The
conductor b501 follows the wall of the air flow channel to the
heater b164. It can be seen that the electrical conductor follows a
non-linear path between the electrical contact b156 and the heater
b164. The second of the conductors follows a similar path on the
opposite side of the air flow channel. It will be understood that
providing the first and second electrical conductors b501 on
opposite sides of the air flow channel provides maximum separation
of the conductors. In another embodiment, not shown, the first and
second electrical conductors b501 may follow paths which are not on
opposite sides of the air flow channel. For example, the first and
second electrical conductors b501 may be positioned on the same
side of the air flow channel.
[0194] An advantage of positioning the electrical conductors along
the sidewall is reducing, or minimizing, disturbance to the air
flow through the air flow channel. Another advantage of positioning
the electrical conductors along the sidewall is reducing, or
minimizing, stress on the electrical conductors. The electrical
conductors are supported and should be less likely to suffer damage
from air flow through the air flow channel.
[0195] The interior volume of the housing between the inlet b172
and the outlet b174 may be called a vaporization chamber. In some
embodiments, part of the interior volume of the housing downstream
of the inlet b172 may be called a plenum chamber. A plenum chamber
is a chamber which allows some conditioning, or settling, of the
air flow before it reaches the wick b162 and the heater b164. In
FIG. 23 the wick b162 and the heater b164 are offset from the air
inlet b172 by an interior volume which may be considered a plenum
chamber. The electrical conductors b501 are routed along an
interior sidewall of the plenum chamber. The electrical conductors
b501 may be bonded to an inner surface of the sidewall of the
plenum chamber.
[0196] FIG. 23 shows a flow modifying device b510 positioned across
the air flow channel, part way between the air inlet b172 and the
wick b162 and the heater b164. The flow modifying device b510 may
take the form of a mesh, grid or some other kind of apertured
element positioned across the air flow channel through the
apparatus. A function of the flow modifying device b510 is to
straighten air flow leading to the wick b162 and the heater b164.
This can reduce turbulence in a vaporization chamber. The flow
modifying device b510 comprises a structure with an upstream side
and a downstream side. The device b510 has a plurality of apertures
extending through it. Each of the apertures extends from the
upstream side to the downstream side. Each of the apertures is
parallel to the longitudinal axis b101 of the air flow channel. In
this embodiment the flow modifying device b510 is a planar
structure, but other shaped devices are possible, such as a curved
or domed profile. The electrical conductors b501 pass through the
flow modifying device b510.
[0197] In FIG. 23 a pair of electrical contacts b156 are shown
positioned near to the longitudinal axis b101 of the consumable. In
other embodiments, the electrical contacts b156 may have a
different position on the end face. For example, a pair of
electrical contacts b156 may be provided which are spaced apart by
a greater distance.
[0198] FIG. 24 shows a consumable b650 according to another
embodiment. The consumable b650 has many features which are the
same as, or similar to, the reference arrangement shown in FIGS. 17
to 20, and to the embodiment of FIG. 23. The consumable b650
comprises a housing with a longitudinal axis b101. The housing has
a first end b551 and a second end b552. An air inlet b172 to the
housing is formed at the first end b551 of the housing. An air
outlet, or mouthpiece, b174 is formed at the second end b552 of the
housing. The internal components of the consumable b550 are similar
to the ones previously described for the reference arrangement. The
consumable has a vaporization chamber with a heater b164 and a wick
b162. The heater b164 generates an aerosol. An air flow channel
extends between the air inlet b172 and the air outlet b174 and
passes through the vaporization chamber.
[0199] At least one electrical contact 156 is provided at the first
end b551 of the housing. In FIG. 23, there is a pair of electrical
contacts b156. The electrical contracts are provided at a central
position, close to the longitudinal axis b101. As described above,
the electrical contacts b156 make contact with corresponding
electrical contacts (not shown) of the main body 120. An electrical
conductor b601 electrically connects an electrical contact b156
with the heater b164. In FIG. 24 there are two electrical
conductors: a first electrical conductor b601 between a first of
the electrical contacts b156 and a first end of the heater b164;
and a second electrical conductor b601 between a second of the
electrical contacts b156 and a second end of the heater b164. In
FIG. 24, the routing of each electrical conductor b601 is a
substantially direct path through the air flow channel itself.
Starting at a first of the electrical contacts b156 at the first
end b551, the conductor b601 is routed axially along the air flow
channel. A major portion of the path between the electrical contact
b156 and the heater b164 is linear, and parallel to the
longitudinal axis b101. In FIG. 24, only the portion of the path
nearest to the heater b164 deviates from this linear path. This
routing can be described as passing through a void of the air flow
channel. Near to the heater b164, the conductor b601 is routed
radially (or diagonally) outwardly to an end of the heater b164.
The second of the conductors follows a similar path on an opposite
side of the longitudinal axis b101 of the air flow channel. An
advantage of routing the electrical conductors in this way is a
more physically direct, i.e., shortest, path. This reduces, or
minimizes, energy losses due to electrical resistance of the
conductors. This can improve battery life and allow a longer
operational period between charges. In another embodiment, not
shown, the first and second electrical conductors may follow paths
which are not on opposite sides of the longitudinal axis of the air
flow channel.
[0200] In FIG. 24, the wick b162 and the heater b164 are offset
from the air inlet b172 by an interior volume which may be
considered a plenum chamber. The electrical conductors b601 are
routed through a void of the plenum chamber. FIG. 24 shows a flow
modifying device b510 positioned across the air flow channel, part
way between the air inlet b172 and the wick b162 and the heater
b164. The flow modifying device b510 is the same as described above
for FIG. 23. The electrical conductors b601 pass through the flow
modifying device b510. The flow modifying device b510 may provide
some structural support for the electrical conductors b601.
[0201] In FIG. 24 a pair of electrical contacts b156 are shown
positioned near to the longitudinal axis b101 of the consumable. In
other embodiments, the electrical contacts b156 may have a
different position on the end face. For example, a pair of
electrical contacts b156 may be provided which are spaced apart by
a greater distance.
[0202] The experimental work reported below is relevant to the
embodiments disclosed above in view of the effect shown by which
the air flow conditions at the wick have an influence on the
particle size of the generated aerosol. The provision of a plenum
chamber and/or a flow conditioning device affects the air flow
conditions at the wick.
Development C
[0203] FIG. 25 shows a smoking substitute apparatus c500 according
to an embodiment of the present disclosure. The smoking substitute
apparatus includes an air inlet c501, located at a bottom end of
the apparatus, and an air outlet c502 located at an opposing upper
end of the apparatus. The inlet and outlet define an air flow
passage therebetween. An aerosol generator c503, of the type
discussed previously, is located between the air inlet and the air
outlet and is configured to generate an aerosol from an aerosol
precursor. Between the aerosol generator and the air inlet c501, is
a flow conditioning module c504 including a plenum chamber.
[0204] The plenum chamber is configurable to include one or more
flow modifying devices c505a and c505b, and one or more spacers
c506a-c506c. The flow modifying devices include or are meshes which
extend across the plenum chamber and so promote a laminar property
to the air flow to the aerosol generator c503. In the example shown
in FIG. 25, the plenum chamber includes a first flow modifying
device c505a located proximal to the air inlet c501, and a second
flow modifying device c505b located between the first flow
modifying device and the aerosol generator c503.
[0205] Between the first and second flow modifying devices c505a
and c505b is a first spacer c506a. This first spacer has a height,
as measured along a longitudinal axis extending from the air inlet
c501 to the air outlet c502 which is approximately equal to the
height of the first and second flow modifying devices. Between the
second flow modifying device c505b and the aerosol generator c504
are second and third spacers c506b and c506c, which are taller than
the first spacer and/or the first and second flow modifying
devices. The spacers both: (i) help define the position of the flow
modifying devices; and (ii) secure the flow modifying devices in
place within the plenum chamber.
[0206] As discussed previously, the flow conditioning module c504
is, in some embodiments, separable from a portion of the apparatus
containing the air outlet. In this example, the flow conditioning
module is separable from a chimney c510 which fluidly connects the
aerosol generator c503 to the air outlet c502. In other examples,
not shown, the flow conditioning module may be separable from the
aerosol generator c503.
[0207] A flow conditioning module c504 is shown, separated from the
remaining smoking substitute apparatus, in FIGS. 26A-26D. Each flow
conditioning module is in a different configuration with respect to
the number and/or placement of the flow modifying devices and
spacers. Common to all modules however, are coil and wick holder
c507 and shroud c508. The shroud c508 cooperatively engages with a
corresponding fixture in the smoking substitute apparatus to define
an aerosol generator chamber in which the aerosol generator
resides. The coil and wick holder c507 provides: (i) electrical
connection from a coil in the aerosol generator to electrodes c511
on the bottom of the module c504; and (ii) provides a holder for a
wick which is to in fluid communication with aerosol precursor.
[0208] In the example shown in FIG. 26A, a single flow modifying
device c601 is located proximal to the air inlet c501. Next, in a
series of elements moving towards the coil and wick holder c507,
are first c602a, second c602b, and third c602c spacers. These
spacers secure the flow modifying device c601, and assist in
defining the location of the flow modifying device c601 within the
plenum chamber. FIG. 26B shows the reverse configuration to that
shown in FIG. 26A, in that the flow modifying device c604 is now
the distal most element from the air inlet c501. Between the flow
modifying device and the air inlet are first c603a, second c603b,
and third c603c spacers. The first spacer being proximal to the air
inlet. FIG. 26C shows a further variant, in which the third spacer
and the flow modifying device have been swapped, and so now the
flow modifying device c606 is located between the third spacer
c605c and the second spacer c605b. This allows the distance between
the flow modifying device and the coil and wick holder to be
varied.
[0209] A further variant is shown in FIG. 26D. This variant differs
from those shown in FIGS. 26A-26C in that the spacers are shorter
than shown previously. Here, in FIG. 26D, four flow modifying
devices c607a-c607d are within the plenum chamber. A first flow
modifying device c607a is located proximal to the air inlet c501,
and a fourth flow modifying device c607d is located proximal to the
coil and wick holder. Interposed between the four flow modifying
devices c607a-c607d are three spacers c608a-c508c. These spacers
are shorter than those shown previously, and have a height
approximately equal to the height of each of the flow modifying
devices. As will be appreciated, this allows any one of the spacers
to be interchanged with any one of the flow modifying devices or
vice versa. Each configuration may have a different effect on the
size of aerosolized particles.
EXAMPLES
[0210] The examples and experimental work presented below are
relevant to the embodiments disclosed above in that the results
indicate that the conditions of the airflow at the wick have an
effect on the particle size of the generated aerosol.
[0211] There now follows a disclosure of certain examples of
experimental work undertaken to determine the effects of certain
conditions in the smoking substitute apparatus on the particle size
of the generated aerosol. However, the present disclosure is to be
understood to not be limited in its application to the specific
experimentation, results, and laboratory procedures disclosed
herein after. Rather, the Examples are simply provided as one of
various embodiments and are meant to be exemplary, not
exhaustive.
Introduction
[0212] Aerosol droplet size is a considered to be an important
characteristic for smoking substitution devices. Droplets in the
range of 2-5 .mu.m are preferred in order to achieve improved
nicotine delivery efficiency and to minimize the hazard of
second-hand smoking. However, at the time of writing (September
2019), commercial EVP devices typically deliver aerosols with
droplet size averaged around 0.5 .mu.m, and to the knowledge of the
inventors not a single commercially available device can deliver an
aerosol with an average particle size exceeding 1 .mu.m.
[0213] The present inventors speculate, without themselves wishing
to be bound by theory, that there has to date been a lack of
understanding in the mechanisms of e-liquid evaporation, nucleation
and droplet growth in the context of aerosol generation in smoking
substitute devices. The present inventors have therefore studied
these issues in order to provide insight into mechanisms for the
generation of aerosols with larger particles. The present inventors
have carried out experimental and modelling work alongside
theoretical investigations, leading to significant achievements as
now reported.
[0214] This disclosure considers the roles of air velocity, air
turbulence and vapor cooling rate in affecting aerosol particle
size.
Experiments
[0215] In the following examples, a Malvern PANalytical Spraytec
laser diffraction system was employed for the particle size
measurement. In order to limit the number of variables, the same
coil and wick (1.5 ohms Ni--Cr coil, 1.8 mm Y07 cotton wick), the
same e-liquid (1.6% freebase nicotine, 65:35 propylene glycol
(PG)/vegetable glycerin (VG) ratio, no added flavor) and the same
input power (10 W) were used in all experiments. Y07 represents the
grade of cotton wick, meaning that the cotton has a linear density
of 0.7 grams per meter.
[0216] Particle sizes were measured in accordance with ISO
13320:2009(E), which is an international standard on laser
diffraction methods for particle size analysis. This is
particularly well suited to aerosols, because there is an
assumption in this standard that the particles are spherical (which
is a good assumption for liquid-based aerosols). The standard is
stated to be suitable for particle sizes in the range 0.1 micron to
3 mm.
[0217] The results presented here concentrate on the volume-based
median particle size Dv50. This is to be taken to be the same as
the parameter d.sub.50 used above.
First Example: Rectangular Tube Testing
[0218] The work of a first example reported here based on the
inventors' insight that aerosol particle size might be related to:
1) air velocity; 2) flow rate; and 3) Reynolds number. In a given
EVP device, these three parameters are inter-linked to each other,
making it difficult to draw conclusions on the roles of each
individual factor. In order to decouple these factors, experiments
of a first example were carried out using a set of rectangular
tubes having different dimensions. These were manufactured by 3D
printing. The rectangular tubes were 3D printed in an MJP 2500 3D
printer. FIG. 1 illustrates the set of rectangular tubes. Each tube
has the same depth and length but different width. Each tube has an
integral end plate in order to provide a seal against air flow
outside the tube. Each tube also has holes formed in opposing side
walls in order to accommodate a wick.
[0219] FIG. 2 shows a schematic perspective longitudinal cross
sectional view of an example rectangular tube 1170 with a wick 1162
and heater coil 1164 installed. The location of the wick is about
half way along the length of the tube. This is intended to allow
the flow of air along the tube to settle before reaching the
wick.
[0220] FIG. 3 shows a schematic transverse cross sectional view an
example rectangular tube 1170 with a wick 1162 and heater coil 1164
installed. In this example, the internal width of the tube is 12
mm.
[0221] The rectangular tubes were manufactured to have same
internal depth of 6 mm in order to accommodate the standardized
coil and wick, however the tube internal width varied from 4.5 mm
to 50 mm. In this disclosure, the "tube size" is referred to as the
internal width of rectangular tubes.
[0222] The rectangular tubes with different dimensions were used to
generate aerosols that were tested for particle size in a Malvern
PANalytical Spraytec laser diffraction system. An external digital
power supply was dialed to 2.6 A constant current to supply 10 W
power to the heater coil in all experiments. Between two runs, the
wick was saturated manually by applying one drop of e-liquid on
each side of the wick.
[0223] Three groups of experiments were carried out in this study
of a first example: [0224] 1. 1.3 lpm (liters per minute, L
min.sup.-1 or LPM) constant flow rate on different size tubes
[0225] 2. 2.0 lpm constant flow rate on different size tubes [0226]
3. 1 m/s constant air velocity on 3 tubes: i) 5mm tube at 1.4 lpm
flow rate; ii) 8 mm tube at 2.8 lpm flow rate; and iii) 20 mm tube
at 8.6 lpm flow rate.
[0227] Table 1 shows a list of experiments of a first example. The
values in "calculated air velocity" column were obtained by simply
dividing the flow rate by the intersection area at the center plane
of wick. Reynolds numbers (Re) were calculated through the
following equation:
Re = .rho. .times. v .times. L .mu. , ##EQU00001##
[0228] where: .rho. is the density of air (1.225 kg/m.sup.3); v is
the calculated air velocity in table 1; .mu. is the viscosity of
air (1.48.times.10.sup.-1 m.sup.2/s); L is the characteristic
length calculated by:
L = 4 .times. P A , ##EQU00002##
[0229] where: P is the perimeter of the flow path's intersection,
and A is the area of the flow path's intersection.
TABLE-US-00001 TABLE 1 List of experiments in the rectangular tube
study Tube Flow Calculated size rate Reynolds air velocity [mm]
[Ipm] number [m/s] 1.3 Ipm 4.5 1.3 153 1.17 constant 6 1.3 142 0.71
flow rate 7 1.3 136 0.56 8 1.3 130 0.47 10 1.3 120 0.35 12 1.3 111
0.28 20 1.3 86 0.15 50 1.3 47 0.06 2.0 Ipm 4.5 2.0 236 1.81
constant 5 2.0 230 1.48 flow rate 6 2.0 219 1.09 8 2.0 200 0.72 12
2.0 171 0.42 20 2.0 132 0.23 50 2.0 72 0.09 1.0 m/s 5.0 1.4 155
1.00 constant air 8 2.8 279 1.00 velocity 20 8.6 566 1.00
[0230] Five repetition runs were carried out for each tube size and
flow rate combination. Between adjacent runs there were at least 5
minutes wait time for the Spraytec system to be purged. In each
run, real time particle size distributions were measured in the
Spraytec laser diffraction system at a sampling rate of 2500 per
second, the volume distribution median (Dv50) was averaged over a
puff duration of 4 seconds. Measurement results were averaged and
the standard deviations were calculated to indicate errors as shown
in section 4 below.
Second Example: Turbulence Tube Testing
[0231] The Reynolds numbers in Table 1 are all well below 1000,
therefore, it is considered fair to assume all the experiments of a
first example would be under conditions of laminar flow. Further
experiments (of a second example) were carried out and reported in
this section to investigate the role of turbulence.
[0232] Turbulence intensity was introduced as a quantitative
parameter to assess the level of turbulence. The definition and
simulation of turbulence intensity is discussed below.
[0233] Different device designs were considered in order to
introduce turbulence. In the experiments of the second example
reported here, jetting panels were added in the existing 12 mm
rectangular tubes upstream of the wick. This approach enables
direct comparison between different devices as they all have highly
similar geometry, with turbulence intensity being the only
variable.
[0234] FIGS. 4A-4D show air flow streamlines in the four devices
used in this turbulence study of the second example. FIG. 4A is a
standard 12 mm rectangular tube with wick and coil installed as
explained previously, with no jetting panel. FIG. 4B has a jetting
panel located 10 mm below (upstream from) the wick. FIG. 4C has the
same jetting panel 5 mm below the wick. FIG. 4D has the same
jetting panel 2.5 mm below the wick. As can be seen from FIGS.
4B-4D, the jetting panel has an arrangement of apertures shaped and
directed in order to promote jetting from the downstream face of
the panel and therefore to promote turbulent flow. Accordingly, the
jetting panel can introduce turbulence downstream, and the panel
causes higher level of turbulence near the wick when it is
positioned closer to the wick. As shown in FIGS. 4A-4D, the four
geometries gave turbulence intensities of 0.55%, 0.77%, 1.06% and
1.34%, respectively, with FIG. 4A being the least turbulent, and
FIG. 4D being the most turbulent.
[0235] For each of FIGS. 4A-4D, there are shown three modelling
images. The image on the left shows the original image (color in
the original), the central image shows a greyscale version of the
image and the right hand image shows a black and white version of
the image. As will be appreciated, each version of the image
highlights slightly different features of the flow. Together, they
give a reasonable picture of the flow conditions at the wick.
[0236] These four devices were operated to generate aerosols
following the procedure explained above (the first example) using a
flow rate of 1.3 lpm and the generated aerosols were tested for
particle size in the Spraytec laser diffraction system.
Third Example: High Temperature Testing
[0237] This experiment of a third example aimed to investigate the
influence of inflow air temperature on aerosol particle size, in
order to investigate the effect of vapor cooling rate on aerosol
generation.
[0238] The experimental set up of the third example is shown in
FIG. 5. The testing used a Carbolite Gero EHA 12300B tube furnace
3210 with a quartz tube 3220 to heat up the air. Hot air in the
tube furnace was then led into a transparent housing 3158 that
contains the EVP device 3150 to be tested. A thermocouple meter
3410 was used to assess the temperature of the air pulled into the
EVP device. Once the EVP device was activated, the aerosol was
pulled into the Spraytec laser diffraction system 3310 via a
silicone connector 3320 for particle size measurement.
[0239] Three smoking substitute apparatuses (referred to as "pods")
were tested in the study: pod 1 is the commercially available
"myblu optimised" pod (FIG. 6); pod 2 is a pod featuring an
extended inflow path upstream of the wick (FIG. 7); and pod 3 is
pod with the wick located in a stagnant vaporization chamber and
the inlet air bypassing the vaporization chamber but entraining the
vapor from an outlet of the vaporization chamber (FIGS. 8A and
8B).
[0240] Pod 1, shown in longitudinal cross sectional view (in the
width plane) in FIG. 6, has a main housing that defines a tank 160x
holding an e-liquid aerosol precursor. Mouthpiece 154x is formed at
the upper part of the pod. Electrical contacts 156x are formed at
the lower end of the pod. Wick 162x is held in a vaporization
chamber. The air flow direction is shown using arrows.
[0241] Pod 2, shown in longitudinal cross sectional view (in the
width plane) in FIG. 7, has a main housing that defines a tank 160y
holding an e-liquid aerosol precursor. Mouthpiece 154y is formed at
the upper part of the pod. Electrical contacts 156y are formed at
the lower end of the pod. Wick 162y is held in a vaporization
chamber. The air flow direction is shown using arrows. Pod 2 has an
extended inflow path (plenum chamber 157y) with a flow conditioning
element 159y, configured to promote reduced turbulence at the wick
162y.
[0242] FIG. 8A shows a schematic longitudinal cross sectional view
of pod 3. FIG. 8B shows a schematic longitudinal cross sectional
view of the same pod 3 in a direction orthogonal to the view taken
in FIG. 8A. Pod 3 has a main housing that defines a tank 160z
holding an e-liquid aerosol precursor. Mouthpiece 154z is formed at
the upper part of the pod. Electrical contacts 156z are formed at
the lower end of the pod. Wick 162z is held in a vaporization
chamber. The air flow direction is shown using arrows. Pod 3 uses a
stagnant vaporizer chamber, with the air inlets bypassing the wick
and picking up the vapor/aerosol downstream of the wick.
[0243] All three pods were filled with the same e-liquid (1.6%
freebase nicotine, 65:35 PG/VG ratio, no added flavor). Three
experiments of the third example were carried out for each pod: 1)
standard measurement in ambient temperature; 2) only the inlet air
was heated to 50.degree. C.; and 3) both the inlet air and the pods
were heated to 50.degree. C. Five repetition runs were carried out
for each experiment and the Dv50 results were taken and
averaged.
Modelling Work
[0244] In the following examples, modelling work was performed
using COMSOL Multiphysics 5.4, engaged physics include: 1) laminar
single-phase flow; 2) turbulent single-phase flow; 3) laminar
two-phase flow; 4) heat transfer in fluids; and (5) particle
tracing. Data analysis and data visualization were mostly completed
in MATLAB R2019a.
Fourth Example: Velocity modelling
[0245] Air velocity in the vicinity of the wick is believed to play
an important role in affecting particle size. In the first example,
the air velocity was calculated by dividing the flow rate by the
intersection area, which is referred to as "calculated velocity" in
a fourth example. This involves a very crude simplification that
assumes velocity distribution to be homogeneous across the
intersection area.
[0246] In order to increase reliability of the fourth example,
computational fluid dynamics (CFD) modelling was performed to
obtain more accurate velocity values: [0247] 1) The average
velocity in the vicinity of the wick (defined as a volume from the
wick surface to 1 mm away from the wick surface) [0248] 2) The
maximum velocity in the vicinity of the wick (defined as a volume
from the wick surface to 1 mm away from the wick surface)
TABLE-US-00002 [0248] TABLE 2 Average and maximum velocity in the
vicinity of wick surface obtained from CFD modelling. Tube Flow
Calculated Average Maximum size rate velocity* velocity**
Velocity** [mm] [Ipm] [m/s] [m/s] [m/s] 1.3 Ipm 4.5 1.3 1.17 0.99
1.80 constant 6 1.3 0.71 0.66 1.22 flow 7 1.3 0.56 0.54 1.01 rate 8
1.3 0.47 0.46 0.86 10 1.3 0.35 0.35 0.66 12 1.3 0.28 0.27 0.54 20
1.3 0.15 0.15 0.32 50 1.3 0.06 0.05 0.12 2.0 Ipm 4.5 2.0 1.81 1.52
2.73 constant 5 2.0 1.48 1.31 2.39 flow 6 2.0 1.09 1.02 1.87 rate 8
2.0 0.72 0.71 1.31 12 2.0 0.42 0.44 0.83 20 2.0 0.23 0.24 0.49 50
2.0 0.09 0.08 0.19 *Calculated by dividing flow rate with
intersection area **Obtained from CFD modelling
[0249] The CFD model uses a laminar single-phase flow setup. For
each experiment, the outlet was configured to a corresponding
flowrate, the inlet was configured to be pressure-controlled, the
wall conditions were set as "no slip". A 1 mm wide ring-shaped
domain (wick vicinity) was created around the wick surface, and
domain probes were implemented to assess the average and maximum
magnitudes of velocity in this ring-shaped wick vicinity
domain.
[0250] The CFD model of the fourth example outputs the average
velocity and maximum velocity in the vicinity of the wick for each
set of experiments carried out in the first example. The outcomes
are reported in Table 2.
Fifth Example: Turbulence Modelling
[0251] Turbulence intensity (I) is a quantitative value that
represents the level of turbulence in a fluid flow system. It is
defined as the ratio between the root-mean-square of velocity
fluctuations, u', and the Reynolds-averaged mean flow velocity,
U:
I = u ' U = 1 3 .times. ( u x '2 + u y '2 + u z '2 ) u x _ 2 + u y
_ 2 + u z _ 2 = 1 3 .function. [ ( u x - u x _ ) 2 + ( u y - u y _
) 2 + + ( u z - u z _ ) 2 ] u x _ 2 + u y _ 2 + u z _ 2 ,
##EQU00003##
[0252] where u.sub.x, u.sub.y and u.sub.z are the x-, y- and
z-components of the velocity vector, u.sub.x, u.sub.y, and u.sub.z
represent the average velocities along three directions.
[0253] Higher turbulence intensity values represent higher levels
of turbulence. As a rule of thumb, turbulence intensity below 1%
represents a low-turbulence case, turbulence intensity between 1%
and 5% represents a medium-turbulence case, and turbulence
intensity above 5% represents a high-turbulence case.
[0254] In a fifth example, turbulence intensity was obtained from
CFD simulation using turbulent single-phase setup in COMSOL
Multiphysics. For each of the four experiments explained in the
second example, above, the outlet was set to 1.3 lpm, the inlet was
set to be pressure-controlled, and all wall conditions were set to
be "no slip".
[0255] Turbulence intensity of the fifth example was assessed
within the volume up to 1 mm away from the wick surface (defined as
the wick vicinity domain). For the four experiments explained in
the second example, the turbulence intensities are 0.55%, 0.77%,
1.06% and 1.34%, respectively, as also shown in FIGS. 4A-4D.
Sixth Example: Cooling rate modelling
[0256] The cooling rate modelling of the sixth example involves
three coupling models in COMSOL Multiphysics: 1) laminar two-phase
flow; 2) heat transfer in fluids, and 3) particle tracing. The
model is setup in three steps:
(1) Set Up Two Phase Flow Model
[0257] Laminar mixture flow physics was selected for the sixth
example. The outlet was configured in the same way as in the fourth
example. However, this model of the sixth example includes two
fluid phases released from two separate inlets: the first one is
the vapor released from wick surface, at an initial velocity of
2.84 cm/s (calculated based on 5 mg total particulate mass over 3
seconds puff duration) with initial velocity direction normal to
the wick surface; the second inlet is air influx from the base of
tube, the rate of which is pressure-controlled.
(2) Set Up Two-Way Coupling With Heat Transfer Physics
[0258] The inflow and outflow settings in heat transfer physics was
configured in the same way as in the two-phase flow model. The air
inflow was set to 25.degree. C., and the vapor inflow was set to
209.degree. C. (boiling temperature of the e-liquid formulation).
In the end, the heat transfer physics is configured to be two-way
coupled with the laminar mixture flow physics. The above model
reaches steady state after approximately 0.2 second with a step
size of 0.001 second.
(3) Set Up Particle Tracing
[0259] A wave of 2000 particles were release from wick surface at
t=0.3 second after the two-phase flow and heat transfer model has
stabilized. The particle tracing physics has one-way coupling with
the previous model, which means the fluid flow exerts dragging
force on the particles, whereas the particles do not exert
counterforce on the fluid flow. Therefore, the particles function
as moving probes to output vapor temperature at each timestep.
[0260] The model of the sixth example outputs average vapor
temperature at each time steps. A MATLAB script was then created to
find the time step when the vapor cools to a target temperature
(50.degree. C. or 75.degree. C.), based on which the vapor cooling
rates were obtained (Table 3).
TABLE-US-00003 TABLE 3 Average vapor cooling rate obtained from
Multiphysics modelling. Tube Flow Cooling rate Cooling rate size
rate to 50.degree. C. to 75.degree. C. [mm] [Ipm] [.degree. C./ms]
[.degree. C./ms] 1.3 Ipm 4.5 1.3 11.4 44.7 constant 6 1.3 5.48 14.9
flow 7 1.3 3.46 7.88 rate 8 1.3 2.24 5.15 10 1.3 1.31 2.85 12 1.3
0.841 1.81 20 1.3 0* 0.536 50 1.3 0 0 2.0 Ipm 4.5 2.0 19.9 670
constant 5 2.0 13.3 67 flow 6 2.0 8.83 26.8 rate 8 2.0 3.61 8.93 12
2.0 1.45 3.19 20 2.0 0.395 0.761 50 2.0 0 0 *Zero cooling rate when
the average vapor temperature is still above target temperature
after 0.5 second
Results and Discussions
[0261] Particle size measurement results for the rectangular tube
testing example above (the first example) are shown in Table 4. For
every tube size and flow rate combination, five repetition runs
were carried out in the Spraytec laser diffraction system. The Dv50
values from five repetition runs were averaged, and the standard
deviations were calculated to indicate errors, as shown in Table
4.
[0262] In this section, the roles of different factors affecting
aerosol particle size will be discussed based on experimental and
modelling results.
TABLE-US-00004 TABLE 4 Particle size measurement results for the
rectangular tube testing. Dv50 Tube Flow Dv50 standard size rate
average deviation [mm] [Ipm] [.mu.m] [.mu.m] 1.3 Ipm 4.5 1.3 0.971
0.125 constant 6 1.3 1.697 0.341 flow rate 7 1.3 2.570 0.237 8 1.3
2.705 0.207 10 1.3 2.783 0.184 12 1.3 3.051 0.325 20 1.3 3.116
0.354 50 1.3 3.161 0.157 2.0 Ipm 4.5 2.0 0.568 0.039 constant 5 2.0
0.967 0.315 flow rate 6 2.0 1.541 0.272 8 2.0 1.646 0.363 12 2.0
3.062 0.153 20 2.0 3.566 0.260 50 2.0 3.082 0.440 1.0 m/s 5.0 1.4
1.302 0.187 constant air 8 2.8 1.303 0.468 velocity 20 8.6 1.463
0.413
Seventh Example: Decouple the Factors Affecting Particle Size
[0263] The particle size (Dv50) experimental results of a seventh
example are plotted against calculated air velocity in FIG. 9. The
graph shows a strong correlation between particle size and air
velocity.
[0264] Different size tubes were tested at two flow rates: 1.3 lpm
and 2.0 lpm . Both groups of data show the same trend that slower
air velocity leads to larger particle size. The conclusion was made
more convincing by the fact that these two groups of data overlap
well in FIG. 9: for example, the 6 mm tube delivered an average
Dv50 of 1.697 .mu.m when tested at 1.3 lpm flow rate, and the 8 mm
tube delivered a highly similar average Dv50 of 1.646 .mu.m when
tested at 2.0 lpm flow rate, as they have similar air velocity of
0.71 and 0.72 m/s, respectively.
[0265] In addition, FIG. 10 shows the results of three experiments
of the seventh example, with highly different setup arrangements:
1) 5 mm tube measured at 1.4 lpm flow rate with Reynolds number of
155; 2) 8 mm tube measured at 2.8 lpm flow rate with Reynolds
number of 279; and 3) 20 mm tube measured at 8.6 lpm flow rate with
Reynolds number of 566. It is relevant that these setup
arrangements have one similarity: the air velocities are all
calculated to be 1 m/s. FIG. 10 shows that, although these three
sets of experiments have different tube sizes, flow rates and
Reynolds numbers, they all delivered similar particle sizes, as the
air velocity was kept constant. These three data points were also
plotted out in FIG. 9 (1 m/s data with star marks) and they tie in
nicely into particle size-air velocity trendline.
[0266] The above results of the seventh example lead to a strong
conclusion that air velocity is an important factor affecting the
particle size of EVP devices. Relatively large particles are
generated when the air travels with slower velocity around the
wick. It can also be concluded that flow rate, tube size and
Reynolds number are not necessarily independently relevant to
particle size, providing the air velocity is controlled in the
vicinity of the wick.
Eighth Example: Further Consideration of Velocity
[0267] In FIG. 9 the "calculated velocity" was obtained by dividing
the flow rate by the intersection area, which is a crude
simplification that assumes a uniform velocity field. In order to
increase reliability of the work, CFD modelling has been performed
to assess the average and maximum velocities in the vicinity of the
wick. In an eighth example, the "vicinity" was defined as a volume
from the wick surface up to 1 mm away from the wick surface.
[0268] The particle size measurement data of the eighth example
were plotted against the average velocity (FIG. 11) and maximum
velocity (FIG. 12) in the vicinity of the wick, as obtained from
CFD modelling.
[0269] The data in these two graphs indicates that in order to
obtain an aerosol with Dv50 larger than 1 .mu.m, the average
velocity should be less than or equal to 1.2 m/s in the vicinity of
the wick and the maximum velocity should be less than or equal to
2.0 m/s in the vicinity of the wick.
[0270] Furthermore, in order to obtain an aerosol with Dv50 of 2
.mu.m or larger, the average velocity should be less than or equal
to 0.6 m/s in the vicinity of the wick and the maximum velocity
should be less than or equal to 1.2 m/s in the vicinity of the
wick.
[0271] It is considered that typical commercial EVP devices deliver
aerosols with Dv50 around 0.5 .mu.m, and there is no commercially
available device that can deliver aerosol with Dv50 exceeding 1
.mu.m. It is considered that typical commercial EVP devices have
average velocity of 1.5-2.0 m/s in the vicinity of the wick.
Ninth Example: The Role of Turbulence
[0272] The role of turbulence has been investigated in terms of
turbulence intensity in a ninth example, which is a quantitative
characteristic that indicates the level of turbulence. In the ninth
example, four tubes of different turbulence intensities were used
to general aerosols which were measured in the Spraytec laser
diffraction system. The particle size (Dv50) experimental results
of the ninth example are plotted against turbulence intensity in
FIG. 13.
[0273] The graph suggests a correlation between particle size and
turbulence intensity, that lower turbulence intensity is beneficial
for obtaining larger particle size. It is noted that when
turbulence intensity is above 1% (medium-turbulence case), there
are relatively large measurement fluctuations. In FIG. 13, the tube
with a jetting panel 10 mm below the wick has the largest error
bar, because air jets become unpredictable near the wick after
traveling through a long distance.
[0274] The results of the ninth example clearly indicate that
laminar air flow is favorable for the generation of aerosols with
larger particles, and that the generation of large particle sizes
is jeopardized by introducing turbulence. In FIG. 13, the 12 mm
standard rectangular tube (without jetting panel) delivers above 3
.mu.m particle size (Dv50). The particle size values reduced by at
least a half when jetting panels were added to introduce
turbulence.
Tenth Example: Vapor Cooling Rate
[0275] FIG. 14 shows the high temperature testing results of a
tenth example. Larger particle sizes were observed from all 3 pods
when the temperature of inlet air increased from room temperature
(23.degree. C.) to 50.degree. C. When the pods were heated as well,
two of the three pods saw even larger particle size measurement
results, while pod 2 was unable to be measured due to significant
amount of leakage.
[0276] Without wishing to be bound by theory, the results of the
tenth example are in line with the inventors' insight that control
over the vapor cooling rate provides an important degree of control
over the particle size of the aerosol. As reported above, the use
of a slow air velocity can have the result of the formation of an
aerosol with large Dv50. It is considered that this is due to
slower air velocity allowing a slower cooling rate of the
vapor.
[0277] Another conclusion related to laminar flow can also be
explained by a cooling rate theory of the tenth example: laminar
flow allows slow and gradual mixing between cold air and hot vapor,
which means the vapor can cool down in slower rate when the airflow
is laminar, resulting in larger particle size.
[0278] The results in FIG. 14 further validate this cooling rate
theory of the tenth example: when the inlet air has higher
temperature, the temperature difference between hot vapor and cold
air becomes smaller, which allows the vapor to cool down at a
slower rate, resulting in larger particle size; when the pods were
heated as well, this mechanism was exaggerated even more, leading
to an even slower cooling rate and an even larger particle
size.
Eleventh Example: Further Consideration of Vapor Cooling Rate
[0279] In the sixth example, the vapor cooling rates for each tube
size and flow rate combination were obtained via multiphysics
simulation. In FIG. 15 and FIG. 16, the particle size measurement
results were plotted against vapor cooling rate to 50.degree. C.
and 75.degree. C., respectively.
[0280] The data in these graphs indicates that in order to obtain
an aerosol with Dv50 larger than 1 .mu.m, the apparatus should be
operable to require more than 16 ms for the vapor to cool to
50.degree. C., or an equivalent (simplified to an assumed linear)
cooling rate being slower than 10.degree. C./ms. From an
alternative viewpoint, in order to obtain an aerosol with Dv50
larger than 1 .mu.m, the apparatus should be operable to require
more than 4.5 ms for the vapor to cool to 75.degree. C., or an
equivalent (simplified to an assumed linear) cooling rate slower
than 30.degree. C./ms.
[0281] Furthermore, in order to obtain an aerosol with Dv50 of 2
.mu.m or larger, the apparatus should be operable to require more
than 32 ms for the vapor to cool to 50.degree. C., or an equivalent
(simplified to an assumed linear) cooling rate being slower than
5.degree. C./ms. From an alternative viewpoint, in order to obtain
an aerosol with Dv50 of 2 .mu.m or larger, the apparatus should be
operable to require more than 13 ms for the vapor to cool to
75.degree. C., or an equivalent (simplified to an assumed linear)
cooling rate slower than 10.degree. C./ms.
Conclusions of Particle Size Experimental Work
[0282] In the above example, particle size (Dv50) of aerosols
generated in a set of rectangular tubes was studied in order to
decouple different factors (flow rate, air velocity, Reynolds
number, tube size) affecting aerosol particle size. It is
considered that air velocity is an important factor affecting
particle size--slower air velocity leads to larger particle size.
When air velocity was kept constant, the other factors (flow rate,
Reynolds number, tube size) has low influence on particle size.
[0283] The role of turbulence was also investigated in the above
examples. It is considered that laminar air flow favors generation
of large particles, and introducing turbulence deteriorates
(reduces) the particle size.
[0284] Modelling methods were used in some of the above examples to
simulate the average air velocity, the maximum air velocity, and
the turbulence intensity in the vicinity of the wick. A COMSOL
model with three coupled physics has also been developed to obtain
the vapor cooling rate.
[0285] All experimental and modelling results of the above examples
support a cooling rate theory that slower vapor cooling rate is a
significant factor in ensuring larger particle size. Slower air
velocity, laminar air flow and higher inlet air temperature lead to
larger particle size, because they all allow vapor to cool down at
slower rates.
[0286] The features disclosed in the foregoing description, or in
the following claims, or in the accompanying drawings, or in the
above examples, expressed in their specific forms or in terms of a
means for performing the disclosed function, or a method or process
for obtaining the disclosed results, as appropriate, may,
separately, or in any combination of such features, be utilized for
realizing the disclosure in diverse forms thereof.
[0287] While the disclosure has been described in conjunction with
the exemplary embodiments and examples described above, many
equivalent modifications and variations will be apparent to those
skilled in the art when given this disclosure. Accordingly, the
exemplary embodiments and examples of the disclosure set forth
above are considered to be illustrative and not limiting. Various
changes to the described embodiments may be made without departing
from the spirit and scope of the disclosure.
[0288] For the avoidance of any doubt, any theoretical explanations
provided herein are provided for the purposes of improving the
understanding of a reader. The inventors do not wish to be bound by
any of these theoretical explanations.
[0289] Any section headings used herein are for organizational
purposes only and are not to be construed as limiting the subject
matter described.
[0290] Throughout this specification, including the claims which
follow, unless the context requires otherwise, the words "have",
"comprise", and "include", and variations such as "having",
"comprises", "comprising", and "including" will be understood to
imply the inclusion of a stated integer or step or group of
integers or steps but not the exclusion of any other integer or
step or group of integers or steps.
[0291] It must be noted that, as used in the specification and the
appended claims, the singular forms "a," "an," and "the" include
plural referents unless the context clearly dictates otherwise.
Ranges may be expressed herein as from "about" one particular
value, and/or to "about" another particular value. When such a
range is expressed, another embodiment includes from the one
particular value and/or to the other particular value. Similarly,
when values are expressed as approximations, by the use of the
antecedent "about," it will be understood that the particular value
forms another embodiment. The term "about" in relation to a
numerical value is optional and means, for example, +/-10%.
[0292] The words "preferred" and "preferably" are used herein refer
to embodiments of the disclosure that may provide certain benefits
under some circumstances. It is to be appreciated, however, that
other embodiments may also be preferred under the same or different
circumstances. The recitation of one or more preferred embodiments
therefore does not mean or imply that other embodiments are not
useful, and is not intended to exclude other embodiments from the
scope of the disclosure, or from the scope of the claims.
Illustrative Embodiments
[0293] In the following illustrative embodiments, numbered
"clauses" set out statements of broad combinations of novel and
inventive features of the present disclosure herein disclosed.
Development B
[0294] B1. A smoking substitute apparatus comprising:
[0295] a housing having a longitudinal axis, the housing having a
first end and a second end;
[0296] an air inlet at the first end of the housing;
[0297] an air outlet at the second end of the housing; [0298] an
aerosol generation chamber comprising an aerosol generator for
generating an aerosol from an aerosol precursor; [0299] an air flow
channel extending between the air inlet and the air outlet and
passing through the aerosol generation chamber; [0300] a plenum
chamber positioned in the air flow channel upstream of the aerosol
generation chamber, the plenum chamber being configured to
condition, in use, the air flow before reaching the aerosol
generator in the aerosol generation chamber;
[0301] at least one electrical contact at the first end of the
housing; [0302] at least one electrical conductor electrically
connecting the at least one electrical contact to the aerosol
generator; [0303] wherein at least a portion of the at least one
electrical conductor is positioned along a sidewall of the plenum
chamber.
[0304] B2. A smoking substitute apparatus according to clause B1
wherein the at least one electrical conductor is positioned along
the sidewall of the air flow channel along its length.
[0305] B3. A smoking substitute apparatus according to clause B1 or
B2 wherein the at least one electrical conductor follows a
non-linear path between the at least one electrical contact and the
aerosol generator.
[0306] B4. A smoking substitute apparatus according to any one of
the preceding clauses B1. to B3 wherein the plenum chamber has a
length along the longitudinal axis of at least 5 mm.
[0307] B5. A smoking substitute apparatus according to any one of
the preceding clauses B1. to B4 comprising a flow modifying device
extending across the air flow channel at a position between the air
inlet and the aerosol generator, wherein the at least one
electrical conductor passes through the flow modifying device.
[0308] B6. A smoking substitute apparatus according to any one of
the preceding clauses B1. to B5 wherein the at least one electrical
conductor is bonded to an inner surface of the sidewall of the
plenum chamber.
[0309] B7. A smoking substitute apparatus according to any one of
the preceding clauses B1. to B6 wherein there is a first electrical
contact and a second electrical contact, a first electrical
conductor electrically connecting the first electrical contact to
the aerosol generator and a second electrical conductor
electrically connecting the second electrical contact to the
aerosol generator, and wherein the first electrical conductor and
the second electrical conductor are positioned on opposing parts of
the sidewall, or on opposing sidewalls, of the air flow
channel.
[0310] B8. A smoking substitute apparatus comprising:
[0311] a housing having a longitudinal axis, the housing having a
first end and a second end;
[0312] an air inlet at the first end of the housing;
[0313] an air outlet at the second end of the housing; [0314] an
aerosol generation chamber comprising an aerosol generator for
generating an aerosol from an aerosol precursor; [0315] an air flow
channel extending between the air inlet and the air outlet and
passing through the aerosol generation chamber; [0316] a plenum
chamber positioned in the air flow channel upstream of the aerosol
generation chamber, the plenum chamber being configured to
condition, in use, the air flow before reaching the aerosol
generator in the aerosol generation chamber; [0317] at least one
electrical contact at the first end of the housing; [0318] at least
one electrical conductor electrically connecting the at least one
electrical contact to the aerosol generator; [0319] wherein at
least a portion of the at least one electrical conductor extends
directly through a void in the air flow channel, out of contact
with a sidewall of the plenum chamber.
[0320] B9. A smoking substitute apparatus according to clause B8
wherein a major portion of the at least one electrical conductor
follows a path which is parallel to the longitudinal axis.
[0321] B10. A smoking substitute apparatus according to clause B8
or B9 wherein the plenum chamber has a length along the
longitudinal axis of at least 5 mm.
[0322] B11. A smoking substitute apparatus according to any one of
clauses B8 to B10 comprising a flow modifying device extending
across the air flow channel at a position between the air inlet and
the aerosol generator, wherein the at least one electrical
conductor passes through the flow modifying device, the flow
modifying device providing support to the at least one electrical
conductor.
[0323] B12. A smoking substitute system comprising:
[0324] a main body having one or more electrical contacts connected
to, or connectable to, a power source in the main body; and
[0325] a smoking substitute apparatus according to any of the
preceding clauses B1 to B11.
Development C
[0326] C1. A smoking substitute apparatus comprising: [0327] an air
inlet and an air outlet, wherein the air inlet is in fluid
communication with the air outlet through an air flow passage;
[0328] an aerosol generator, located in the air flow passage and
configured to generate an aerosol from an aerosol precursor; and
[0329] a plenum chamber, disposed in the air flow passage upstream
of the aerosol generator and being configurable to include at least
one flow modifying device extending across the air flow passage at
a position between the air inlet and the aerosol generator; [0330]
wherein the flow modifying device is configured to affect a
characteristic of the air flow to the aerosol generator, the
position of the flow modifying device in the plenum chamber being
selectable between at least two positions to affect the
characteristic of the air flow presented to the aerosol
generator.
[0331] C2. The smoking substitute apparatus of clause C1, wherein
the plenum chamber is contained within a flow conditioning module,
separable from the air outlet.
[0332] C3. The smoking substitute apparatus of either clause C1 or
clause C2, wherein the plenum chamber is configurable to include a
plurality of flow modifying devices.
[0333] C4. The smoking substitute apparatus of any preceding clause
C1 to C3, wherein the plenum chamber is configurable to include one
or more spacers within the plenum chamber, the one or more spacers
being configured to assist in defining the position of the flow
modifying device(s) in the plenum chamber.
[0334] C5. The smoking substitute apparatus of clause C4, wherein
there is a plurality of spacers, which are configured to be
interchangeable within the plenum chamber, so as to allow the
repositioning of the flow modifying device(s) within the plenum
chamber.
[0335] C6. The smoking substitute apparatus of clause C5, wherein
two or more of the plurality of spacers have differing
geometries.
[0336] C7. The smoking substitute apparatus of any preceding clause
C1 to C6, wherein the plenum chamber is configurable to include a
plurality of flow modifying devices which are interchangeable
within the plenum chamber, each flow modifying device affecting the
characteristic of the air flow differently.
[0337] C8. The smoking substitute apparatus of clause C7 as
dependent on any of clauses C4 to C6, wherein the spacers and the
plurality of flow modifying devices are interchangeable within the
plenum chamber.
[0338] C9. The smoking substitute apparatus of any preceding clause
C1 to C8, wherein the flow modifying device(s) are meshes.
[0339] C10. The smoking substitute apparatus of any preceding
clause C1 to C9, wherein the flow modifying device is configured to
promote a laminar property to the air flow to the aerosol
generator.
[0340] C11. A flow conditioning module, attachable to an aerosol
generator of a smoking substitute apparatus, the flow conditioning
module comprising a plenum chamber, the plenum chamber defining an
air flow passage therethrough, and being configurable to include at
least one flow modifying device extending across the air flow
passage and wherein the flow modifying device is configured to
promote a laminar property to the air flow to the aerosol
generator.
[0341] C12. A kit, comprising: [0342] a flow conditioning module,
attachable to an aerosol generator of a smoking substitute
apparatus, the flow conditioning module including a plenum chamber
defining an air flow passage therethrough, and being configurable
to include at least one flow modifying device extending across the
air flow passage; and [0343] one or more flow modifying devices,
configured to promote a laminar property to the air flow to the
aerosol generator.
[0344] C13. The kit of clause C12, further comprising one or more
spacers, configured to assist in defining the position of the flow
modifying devices in the plenum chamber.
[0345] C14. A method of manufacturing a smoking substitute
apparatus, the smoking substitute apparatus including: [0346] an
air inlet and an air outlet, wherein the air inlet is in fluid
communication with the air outlet through an airflow passage;
[0347] an aerosol generator, located in the air flow passage and
configured to generate an aerosol from an aerosol precursor; and
[0348] engagement means, suitable for connected to a flow
conditioning module; wherein the method includes: [0349] attaching
the flow conditioning module to the engagement means, the flow
conditioning module including a plenum chamber, the plenum chamber
thereby being disposed in the air flow passage upstream of the
aerosol generator, and at least one flow modifying device extending
across the air flow passage at a point between the air inlet and
the aerosol generator; [0350] wherein the flow modifying device is
configured to affect a characteristic of the air flow to the
aerosol generator, the position of the flow modifying device in the
plenum chamber being selectable between at least two positions to
affect the characteristic of the air flow presented to the aerosol
generator.
[0351] C15. A smoking substitute apparatus, suitable for use with
the flow conditioning module of clause C11, wherein the smoking
substitute apparatus includes: [0352] an air inlet and an air
outlet, wherein the air inlet is in fluid communication with the
air outlet through an air passage; and [0353] an aerosol generator,
located in the air flow passage and configured to generate [0354]
an aerosol from an aerosol precursor; and [0355] an engagement
means, suitable for connection to the flow conditioning module.
* * * * *