Electrostatic aerosol partitioning device and method of use

Abstract

The invention relates to an electrostatic aerosol partitioning device comprising an aerosol inlet portion for introduction of an aerosol into the electrostatic aerosol partitioning device, an aerosol charging portion for charging the particles comprised in the aerosol, and an aerosol separation portion configured to generate an electrostatic field acting on the charged particles to separate the charged particles from the aerosol. A gas sampling line is provided in the separation portion and the gas sampling line is configured to establish an anisoaxial gas flow with respect to the entry flow direction of the aerosol into the aerosol separation portion.

Description

[0001] New PCT Patent Application October 15, 2025 Philip Morris Products S.A. 46102- PCT

[0002] -1-

[0003] ELECTROSTATIC AEROSOL PARTITIONING DEVICE AND METHOD OF USE

[0004] The present invention relates to an electrostatic aerosol partitioning device and a method of using such device to generate and sample particle-free gas phase from an aerosol. The method may particularly be used for analytical processing of an aerosol obtained from an aerosol-generating device.

[0005] Aerosols are defined as liquid and / or solid particles suspended in a gas. In many naturally occurring or anthropogenic aerosols the gas phase is air and the particulate phase consists of solid, dry particles. For these aerosols, a clear allocation of aerosol constituents to the two phases is possible.

[0006] However, if chemical species with relevant vapor pressures at room temperature are present in the aerosol, the partitioning of aerosol constituents between the particulate phase (liquid particles or the liquid fraction present on solid particles) and the gas phase is more complex. Typically, in such cases the aerosol evolves towards its thermodynamic equilibrium at which the kinetics of evaporation equal the kinetics of condensation / nucleation / dissolution of the suspended particles and no net mass flux between the two phases occurs. Aerosols in which such complex and dynamic partitioning may be observed include combustion products, kitchen fumes or aerosols generated by combustible or non-combustible aerosol-generating devices.

[0007] A deep understanding of aerosol partitioning is critical in various technological and scientific fields, as it has a major impact on how aerosols evolve over time and how they interact with or deposit on solid or liquid surfaces. For example, during the inhalation of complex aerosols such as the ones produced, for instance, by combustible cigarettes, it is well documented that aerosol partitioning changes dynamically due to changes in temperature, humidity, and pressure and that particulate and gaseous aerosol constituents reach different regions of the respiratory tract with different efficiencies and deposit there with different kinetics.

[0008] WO 2003 / 061836 is directed to an electrostatic aerosol partitioner designed to generate a particle-depleted and a particle enriched flow. A flow separator allows to separate these flows and to subject these flows to further analyses. The flow splitter used in the separation zone is an isokinetically and isoaxially operating flow splitter. Such flow splitters bear a risk of sampling undesired particles in the gas sampling line. In particular large particles, which are of lowest electrical mobility and carry a large mass, may strongly contaminate a gas sample. Due to their naturally low occurrence in the native aerosol, such artifactually sampled particulate phase constituents are likely to increase their concentrations in the collected samples by orders of magnitude relative to the gas phase of the native aerosol. New PCT Patent Application October 15, 2025 Philip Morris Products S.A. 46102- PCT

[0009] -2-

[0010] Furthermore, particles deposited on one of the electrodes of the device may remain in the device and may evaporate from the electrode at a later stage, which again leads to a contamination of the collected gas phase. These negative effects may be reduced by using a short separation zone or large device diameters, combined with a high aerosol flow velocity. However, a short separation zone combined with a high aerosol flow velocity bears the risk of inefficient separation of the gas and the particulate aerosol phase. A large device diameter combined with high aerosol flow velocities requires large aerosol volumes to be supplied to the device. For aerosols that are available only in small volumes, as is often the case in laboratory applications, such a device may therefore not be suitable.

[0011] It would be desirable to provide an electrostatic aerosol gas phase sampler that overcomes at least a part of the above-mentioned limitations of the existing prior art. It would be desirable to provide an electrostatic aerosol gas phase sampler that is suitable for highly sensitive downstream analytical processing of the generated, particle-free gas phase.

[0012] It would further be desirable to provide an electrostatic aerosol gas phase sampler that avoids or at least reduces the likelihood of introducing electrochemical artifacts in the sampled phases.

[0013] It would further be desirable to provide an electrostatic aerosol gas phase sampler that is compatible for use with aerosol volume flow rates reaching down to magnitudes of 0.1 cubic centimeters per second. It would be further desirable to provide a method to use such a device to generate and sample particle-free gas phase from an aerosol for analytical processing.

[0014] According to the invention there is provided an electrostatic aerosol partitioning device which may comprise an aerosol inlet portion for introduction of an aerosol into the electrostatic aerosol partitioning device, an aerosol charging portion for charging the particles comprised in the aerosol, and an aerosol separation portion configured to generate an electrostatic field acting on the charged particles to separate the charged particles from the aerosol. A gas sampling line may be provided in the separation portion. The gas sampling line may be configured to establish an anisoaxial gas flow with respect to the entry flow direction of the aerosol into the aerosol separation portion.

[0015] According to an embodiment of the invention there is provided an electrostatic aerosol partitioning device comprising an aerosol inlet portion for introduction of an aerosol into the electrostatic aerosol partitioning device, an aerosol charging portion for charging the particles comprised in the aerosol, and an aerosol separation portion configured to generate an electrostatic field acting on the charged particles to separate the charged particles from the aerosol. A gas sampling line is provided in the separation portion. The gas sampling line is configured to establish an anisoaxial gas flow with respect to the flow direction of the aerosol through the aerosol separation portion. New PCT Patent Application October 15, 2025 Philip Morris Products S.A. 46102- PCT

[0016] -3-

[0017] The term “isoaxial” with respect to a gas flow through a given element, is used herein to denote a gas flow that is directed in the same orientation and parallel to an entry flow direction of the gas into the given element.

[0018] The term “anisoaxial” with respect to a gas flow through a given element, is used herein to denote any gas flow that is not “isoaxial”. Thus, an “anisoaxial gas flow” may either denote a gas flow that is not parallel to an entry flow direction of the gas into the given element, or may denote a gas flow that is parallel but opposite to an entry flow direction of the gas into the given element.

[0019] The present invention allows to overcome at least some of the limitations of existing technologies. In particular, the electrostatic aerosol partitioning device allows for highly sensitive downstream analytical processing of the generated, particle-free gas phase. Furthermore, the electrostatic aerosol partitioning device is compatible with aerosol volume flow rates reaching down to magnitudes of 0.1 cubic centimeters per second and less.

[0020] The electrostatic aerosol partitioning device may further comprise an aerosol outlet portion. The aerosol outlet portion may be connected to a flow generator. The flow generator may be configured as a pumping device. The flow generator may be configured to generate a controlled gas flow through the electrostatic aerosol partitioning device. By establishing a controlled gas flow through the device, well defined sampling conditions may be achieved. Defined sampling conditions are important to allow comparability and reliable analysis of the sampling results.

[0021] The electrostatic aerosol partitioning device may comprise a housing. The housing may define an aerosol channel extending from the aerosol inlet portion, through the aerosol charging portion and the aerosol separation portion towards the aerosol outlet portion.

[0022] The aerosol channel may have a generally cylindrical shape. The aerosol channel may have a circular, elliptical or rectangular cross-section.

[0023] The aerosol channel may be formed from consecutive wall segments of the aerosol inlet portion, the aerosol charging portion, the aerosol separation portion and the aerosol outlet portion. By providing consecutive wall segments, an aerosol channel may be obtained that allows for a constant gas flow velocity through the electrostatic aerosol partitioning device.

[0024] The consecutive wall segments forming the aerosol channel may be electrically insulated from each other. Electrical insulation may be obtained by peripherally extending segments formed from electrically non-conductive material. The cross-sectional shape of the insulating segments may correspond to the cross-sectional shape of the wall segments of the adjacent portions of the electrostatic aerosol partitioning device. Accordingly, the insulating segments may be ring-shaped, and may have a circular, elliptical or rectangular cross-section. New PCT Patent Application October 15, 2025 Philip Morris Products S.A. 46102- PCT

[0025] -4-

[0026] The insulating elements may be formed from suitable electrically non-conductive material. Preferably the insulating elements may be formed from synthetic polymer or ceramic material.

[0027] The aerosol channel may have a total length of between 2 and 50 centimeters. The aerosol channel may have a total length of between 5 and 30 centimeters. The aerosol channel may have a total length of between 10 and 20 centimeters.

[0028] The aerosol channel may have an inner diameter of between 1 and 10 centimeters. The aerosol channel may have an inner diameter of between 2 and 8 centimeters. The aerosol channel may have an inner diameter of between 3 and 6 centimeters.

[0029] The aerosol channel may have a cross-sectional area that varies along the length of the aerosol channel. By varying the cross-sectional area a constant gas flow velocity within the aerosol channel of the electrostatic aerosol partitioning device may be achieved.

[0030] The wall segment of the aerosol charging portion may have a conical or inwardly tapering geometry to achieve a constant gas flow velocity within the aerosol charging portion. The wall segment of the aerosol separation portion may have a conical or inwardly tapering geometry to achieve a constant gas flow velocity within the aerosol separation portion. In both of these portions, gas volume may be taken from the aerosol channel. The loss of gas volume may lead to a reduced gas flow velocity in these portions. By providing one or both of these portions with such reducing cross-section, the loss of gas volume may be compensated, and the gas flow velocity in these portions may be retained at a constant level.

[0031] The aerosol inlet portion may be configured to be connected to an aerosol source. The aerosol inlet portion may in particular be configured to be connected to an aerosol-generating device. The aerosol-generating device may be a non-combustible aerosol-generating device. The aerosol-generating device may be an electrically operated aerosol-generating device. The aerosol-generating device may be a Heat-Not-Burn (HNB) aerosol-generating device.

[0032] Aerosol partitioning is critical in various technological and scientific fields, as it has a major impact on how aerosols evolve over time and how they interact with or deposit on solid or liquid surfaces. For example, during the inhalation of complex aerosols such as the ones produced by electronic or combustible aerosol-generating devices, it is well documented that aerosol partitioning changes dynamically due to changes in temperature, humidity, and pressure and that particulate and gaseous aerosol constituents reach different regions of the respiratory tract with different efficiencies and deposit there with different kinetics.

[0033] A deep understanding on the partitioning of an aerosol before inhalation and how it changes during inhalation is, therefore, crucial to understand or predict the deposition patterns within the respiratory tract, which ultimately defines the potential toxicological impact and the consumer’s perception of the inhalation. New PCT Patent Application October 15, 2025 Philip Morris Products S.A. 46102- PCT

[0034] -5-

[0035] Theoretical models allow to predict aerosol partitioning if basic physicochemical properties of the aerosol constituents are known. In practice, ideality of the liquid comprising the particulate fraction of an aerosol is commonly not provided, vapor pressures, mol fractions and Henry constants of the aerosol constituents are often not known and although they can be determined in bulk liquids using routine methodologies, obtained values cannot by implication be assumed to be valid for the conditions in an aerosol. Thus, the electrostatic aerosol partitioning device of the present invention may be particularly useful for analytical purposes in the context of, for instance, the development and application of computational models for predicting aerosol partitioning in aerosol-generating devices.

[0036] The aerosol inlet portion may comprise an additional opening configured to be connected to the environment or to a device which is configured to generate a constant gas flow towards this additional opening. In this way additional control may be obtained and changes in the aerosol output of the aerosol-generating device that is connected to the aerosol inlet portion may be compensated.

[0037] The aerosol charging portion may comprise a charger electrode. The charger electrode may be configured as a corona discharger. The charger electrode may be configured to produce a high concentration of ions. These ions may interact with the aerosol and may particularly serve for charging the particles of the aerosol.

[0038] The charger electrode may be centrally located within the aerosol charging portion. In this way the aerosol may be uniformly guided around the charger electrode. This may maximise charging action in the aerosol charging portion.

[0039] The charger electrode may be a tungsten electrode configured for application of a positive electrostatic potential of more than 5 kilovolts.

[0040] The charger electrode may be surrounded by a permeable grid electrode. The permeable grid electrode may be configured for application of a positive electrostatic potential of up to 1 kilovolt.

[0041] The aerosol charging portion may comprise a plurality of charger electrodes. The charger electrodes may be mounted symmetrically within the aerosol charging portion. The charger electrodes may be mounted at circumferential openings in the wall segment of the aerosol channel of the aerosol charging portion.

[0042] The wall segment of the aerosol channel of the aerosol charging portion may be configured to be electrically conductive. The wall segment of the aerosol channel of the aerosol charging portion may be electrically grounded. The wall segment of the aerosol channel of the aerosol charging portion may be connected to an alternating voltage source operated at a frequency of up to 50 Hertz. New PCT Patent Application October 15, 2025 Philip Morris Products S.A. 46102- PCT

[0043] -6-

[0044] The wall segment of the aerosol channel of the aerosol charging portion may be configured to be gas permeable. The wall segment of the aerosol channel of the aerosol charging portion may be made of one of a woven mesh, a machined mesh, a conductive porous material such as an open-celled metal foam, a sintered metal powder and sintered metal beads.

[0045] Particles that condense at the wall segment of the aerosol channel of the aerosol charging portion may be adsorbed by the porous material of the wall segment. In this way it may be avoided that condensed material may re-evaporate into the aerosol flow.

[0046] The wall segment of the aerosol channel of the aerosol charging portion may be surrounded by a second wall. The second wall may be made of an insulating and gas- impermeable material. A screen flow chamber may be formed between the outer surface of the wall segment and the second wall. The screen flow chamber may be connected to a pumping device configured to generate a controlled gas flow out of the screen flow chamber.

[0047] Particles that have condensed at the wall segment of the aerosol channel of the aerosol charging portion may be adsorbed by the porous material of the wall segment. The material may be transported through the porous material and may re-evaporate into the screen flow chamber. This re-evaporated material may then be pumped out of the screen flow chamber via the pumping device. In this way, material that condense at the inner wall of the aerosol channel may be efficiently removed from the system. In this way, improved control over the aerosol composition within the aerosol channel is achieved and in particular re-evaporation into the inner volume of the aerosol channel is reduced or may even be avoided.

[0048] The cross-sectional shape of the second wall may correspond to the cross-sectional shape of the aerosol channel. If the aerosol channel has a substantially circular cross-sectional shape, then the second wall may advantageously also have a circular cross-sectional shape. If the aerosol channel has a substantially rectangular cross-sectional shape, then the second wall may advantageously also have a rectangular cross-sectional shape.

[0049] The screen flow chamber may be connected to a plurality of pumping devices configured to generate a controlled gas flow out of the screen flow chamber.

[0050] The electrostatic aerosol partitioning device comprises an aerosol separation portion configured to generate an electrostatic field acting on the charged particles to separate the charged particles from the gaseous aerosol constituents.

[0051] The aerosol separation portion may comprise a first and a second electrode which are configured to generate the electrostatic field.

[0052] The first electrode may be provided in the center of the aerosol separation portion. The first electrode may be provided in the center and along the longitudinal axis of the aerosol separation portion. New PCT Patent Application October 15, 2025 Philip Morris Products S.A. 46102- PCT

[0053] -7-

[0054] The first electrode may be removably mounted in the center of the aerosol separation portion. The first electrode may be mounted by means of one or more spokes extending from the wall segment towards the center of the aerosol separation portion. The one or more spokes may be arranged in radial symmetry and in radial orientation.

[0055] The first electrode may be configured to be connected to a voltage source capable of generating a voltage of up to 5 kilovolts. The first electrode may be configured to be electrically grounded. In either case the electrical connection to the voltage source or the ground may be established by means of wires located within or mounted on one or several of the spokes.

[0056] The second electrode may be formed by or on the wall segments forming the aerosol channel of the aerosol separation portion.

[0057] The second electrode may be configured to be electrically grounded or to be connected to a voltage source capable of generating a negative voltage of up to minus 5 kilovolts.

[0058] By applying an electrostatic field between the two electrodes of the aerosol separation portion, positively charged aerosol particles suspended in the aerosol are redirected towards the second electrode and are captured at the wall segments of the aerosol separating portion. In more detail, charged aerosol particles, which initially follow the aerosol flow from the aerosol charging portion towards the aerosol separation portion are subjected to the radially oriented electrostatic field generated by the electrical potential applied between first electrode and the second electrode of the aerosol separation portion. The electrostatic field results in coulomb forces in the direction of the electrostatic field acting on the charged aerosol particles. The zone close to the first electrode becomes depleted of charged particles, while the periphery of the aerosol channel in vicinity of the second electrode may become enriched in particles. The charged particles may deposit on the second electrode or essentially on any wall segment of the aerosol channel.

[0059] In order to avoid re-evaporation of the adsorbed particles from the surface of the wall segments, the wall segments of the aerosol separation portion may be formed from porous and gas permeable material. The wall segment of the aerosol channel of the aerosol separation portion may be made of one of a woven mesh, a machined mesh, a conductive porous material such as an open-celled metal foam, a sintered metal powder and sintered metal beads.

[0060] Particles that condense at the wall segment of the aerosol channel of the aerosol separation portion may be adsorbed by the porous material of the wall segment. In this way it may be avoided that condensed material may re-evaporate into the aerosol flow.

[0061] The wall segment of the aerosol channel of the aerosol separation portion may also be surrounded by a second wall. The second wall may be made of an insulating and gas- impermeable material. A screen flow chamber may be formed between the outer surface of New PCT Patent Application October 15, 2025 Philip Morris Products S.A. 46102- PCT

[0062] -8- the wall segment and the second wall. The screen flow chamber may be connected to a pumping device configured to generate a controlled gas flow out of the screen flow chamber.

[0063] Particles that have condensed at the wall segment of the aerosol channel of the aerosol separation portion may be absorbed by the porous material of the wall segment. The material may be transported through the porous material and may re-evaporate into the screen flow chamber. This re-evaporated material may then be pumped out of the screen flow chamber via the pumping device. In this way, material that condense at the inner wall of the aerosol channel may be efficiently removed from the system. In this way, improved control over the aerosol composition within the aerosol channel is achieved and in particular re-evaporation into the inner volume of the aerosol channel is reduced or may even be avoided. The screen flow chamber of the aerosol separation portion may be connected to the screen flow chamber of the aerosol charging portion.

[0064] The aerosol separation portion comprises a gas sampling line. The gas sampling line is configured to allow to take representative samples of the gaseous aerosol constituents in the aerosol separation portion.

[0065] The gas sampling line may be provided in the form of a hollow tube. The inlet of the gas sampling line may be provided in the aerosol separation portion.

[0066] The gas sampling line is configured to establish an anisoaxial gas flow with respect to the entry flow direction of the aerosol into the aerosol separation portion.

[0067] The gas sampling line may be located within the aerosol separation portion. The gas sampling line may be located in the center and along the longitudinal axis of the aerosol separation portion. The gas sampling line may be configured to establish a gas sampling flow that is oriented at an angle of 180 degree relative to the entry flow direction of the aerosol into the aerosol separation portion. In other words, the gas sampling line may be configured to establish a gas sampling flow that is parallel but opposite to the entry flow direction of the aerosol into the aerosol separation portion.

[0068] The gas sampling line may be configured to establish a gas sampling flow that is oriented at any angle of between 0 and 180 degrees relative to the entry flow direction of the aerosol into the aerosol separation portion. The gas sampling line may be configured to establish a gas sampling flow that is oriented at any angle of between 90 and 180 degrees relative to the entry flow direction of the aerosol into the aerosol separation portion.

[0069] By sampling the particle-depleted gas phase anisoaxially the likelihood to sample undesired particles is further reduced. Suspended articles, in particular large particles, have a tendency to follow their inertial momentum and to therefore follow a linear trajectory. By sampling the gas phase in an anisoaxial direction uncharged particles may therefore still be removed and excluded from the sampling flow. Accordingly, more precise results regarding New PCT Patent Application October 15, 2025 Philip Morris Products S.A. 46102- PCT

[0070] -9- the composition of the gas phase of the aerosol may be obtained as compared to what is achievable with existing aerosol partitioning devices.

[0071] The hollow tube forming the gas sampling line may be made from an inert material. The hollow tube forming the gas sampling line may be made from an electrically conductive material. The hollow tube forming the gas sampling line may therefore at the same time be configured to form the first electrode of the aerosol separation portion.

[0072] The inlet end of the hollow tube of the aerosol separation portion may be positioned towards a downstream end portion of the separation portion. The inlet end of the hollow tube of the aerosol separation portion may be positioned at the downstream end portion of the separation portion. By locating the inlet end of the hollow tube of the aerosol separation portion towards a downstream end portion of the separation portion, sufficient time is obtained to allow the charged particles to be directed onto the second electrode.

[0073] Thus, the gas phase sampled into the gas sampling line is essentially a particle depleted aerosol. Particles of low electrical mobility (low electrical charge and / or high mass) and particles of zero electrical mobility (no electrical charge) may still be present in the region close to the inlet end of the gas sampling line. Particles that did not acquire electrical charge are essentially unaffected by the electrical field and follow the streamlines of the gas. Such articles, in particular large mass particles may have a sufficiently high flow speed, such that these particles may escape the anisoaxial gas sampling line due to their moment of inertia.

[0074] When the hollow tube of the gas sampling line forms the first electrode, the inlet end of the hollow tube may be formed to have a sharp tip. The electric field generated at the sharp tip of the hollow tube may be significantly stronger than the electrical field along the linear portion of the hollow tube. This electrical field may efficiently prevent particles of low electrical mobility from entering the gas sampling line.

[0075] To avoid the formation of a corona discharge at the inlet end of the tube shaped first electrode, a thickening in the shape of a sphere may be included at the inlet end of the tube shaped first electrode.

[0076] The separation of particulate and gaseous aerosol constituents may be further increased by elongating the aerosol separation portion. The separation of particulate and gaseous aerosol constituents may also be increased by connecting one or more further electrostatic aerosol partitioning devices to the aerosol outlet portion. In case of such cascade of electrostatic aerosol partitioning devices, the gas sampling flow rate may be equal to zero in all electrostatic aerosol partitioning devices except in the last electrostatic aerosol partitioning devices present. New PCT Patent Application October 15, 2025 Philip Morris Products S.A. 46102- PCT

[0077] -10-

[0078] Any aerosol components that did not deposit within the device and are not sampled into the gas sampling line may leave the device through the aerosol outlet portion and may be discarded.

[0079] The gas sampling line of the separation portion may be connected to a device that is configured for generating a controlled gas flow. The gas sampling line of the separation portion may be directed towards a gas trap. Such gas traps are well described in the art and may, for instance, be a cold-trap in which gas phase constituents are condensed using dry-ice or liquid nitrogen as cooling agent. The condensed gas sample may then be subjected to chemical analyses, for instance by mass spectrometry. When furthermore the composition of the native aerosol is determined, such as by trapping it using a combination of filters and cold traps, the partitioning within the native aerosol can be derived.

[0080] The gas phase sampled through the gas sampling line may be directly fed to a mass spectrometer or to a gas chromatograph for immediate compound quantification and identification. The gas phase sampled through the gas sampling line may also be fed to a biological test system for immediate toxicological characterization of the aerosol sample.

[0081] The present invention also relates to a method of electrostatically partitioning an aerosol. The method may comprise the steps of introducing an aerosol into an aerosol inlet portion of an electrostatic aerosol partitioning device, charging particles comprised in the aerosol in an aerosol charging portion, generating in an aerosol separation portion an electrostatic field acting on the charged particles to separate the charged particles from the aerosol and to create a particle depleted aerosol, providing a gas sampling line in the aerosol separation portion and establishing through the gas sampling line an anisoaxial gas flow with respect to the entry flow direction of the aerosol into the aerosol separation portion to sample a gas phase of the particle depleted aerosol.

[0082] In particular this method may be suitable to be used with the electrostatic aerosol partitioning device as described herein.

[0083] The method may further comprise the step of generating a controlled gas flow through the electrostatic aerosol partitioning device with a gas flow generator. To this end, the gas flow generator may be connected to an aerosol outlet portion of the electrostatic aerosol partitioning device.

[0084] The volume flow rate of the aerosol entering the aerosol inlet portion of the electrostatic aerosol partitioning device may correspond to the sum of the volume flow rate QQ exiting the device through the aerosol outlet portion, the volume flow rate Qg exiting the device through the screen flow chamber and the volume flow rate QQ exiting the device via the gas sampling line. New PCT Patent Application October 15, 2025 Philip Morris Products S.A. 46102- PCT

[0085] -11-

[0086] The volume flow rate QQ exiting the device through the aerosol outlet portion may be adjusted to be in the range of 0.15 to 150 cubic centimeters per second. The volume flow rate QQ may be adjusted to be in the range of 0.15 to 100 cubic centimeters per second. The volume flow rate QQ may be adjusted to be in the range of 0.15 to 50 cubic centimeters per second. The volume flow rate QQ exiting the device through the aerosol outlet portion may be about a magnitude larger than the volume flow rate QS.

[0087] The volume flow rate Qg exiting the device through the screen flow chamber may be adjusted to be in the range of 0.015 to 1.5 cubic centimeters per second. The volume flow rate Qg may be adjusted to be in the range of 0.015 to 1.0 cubic centimeters per second. The volume flow rate Qg may be adjusted to be in the range of 0.015 to 0.5 cubic centimeters per second. The volume flow rate Qg may be about one to two magnitudes larger than volume flow rate QQ.

[0088] The volume flow rate QQ exiting the device via the gas sampling line may be adjusted to be in the range of 0.0015 to 0.15 cubic centimeters per second. The volume flow rate Qg may be adjusted to be in the range of 0.0015 to 0.1 cubic centimeters per second. The volume flow rate Qg may be adjusted to be in the range of 0.0015 to 0.05 cubic centimeters per second.

[0089] Considering the above indicated flow rates, it is apparent that sampling into the gas sampling line occurs at a very low volume flow rate QQ as compared to the volume flow rate QQ exiting the device through the aerosol outlet portion. In addition, since the sampling into the gas sampling line is performed anisoaxially, gas sampling is performed in a direction different, preferably opposite, to the gas flow direction in the aerosol separation portion.

[0090] Accordingly, the sampling of residual particles comprised in the aerosol is of very low efficiency. This is particularly true for larger particles having relevant inertial momentum.

[0091] Below, there is provided a non-exhaustive list of non-limiting examples. Any one or more of the features of these examples may be combined with any one or more features of another example, embodiment, or aspect described herein.

[0092] Example 1 : An electrostatic aerosol partitioning device comprising: an aerosol inlet portion for introduction of an aerosol into the electrostatic aerosol partitioning device; an aerosol charging portion for charging the particles comprised in the aerosol; an aerosol separation portion configured to generate an electrostatic field acting on the charged particles to separate the charged particles from the aerosol, New PCT Patent Application October 15, 2025 Philip Morris Products S.A. 46102- PCT

[0093] -12- wherein a gas sampling line is provided in the separation portion and wherein the gas sampling line is configured to establish an anisoaxial gas flow with respect to the entry flow direction of the aerosol into the aerosol separation portion.

[0094] Example 2: The electrostatic aerosol partitioning device according to example 1 , further comprising an aerosol outlet portion.

[0095] Example 3: The electrostatic aerosol partitioning device according to any of the preceding examples, further comprising a housing defining an aerosol channel extending from the aerosol inlet portion to the aerosol outlet portion.

[0096] Example 4: The electrostatic aerosol partitioning device according to any of the preceding examples, wherein the aerosol channel has a generally cylindrical shape with a circular or rectangular cross-section.

[0097] Example 5: The electrostatic aerosol partitioning device according to any of the preceding examples, wherein the aerosol channel is formed from consecutive wall segments of the aerosol inlet portion, the aerosol charging portion, the aerosol separation portion and the aerosol outlet portion.

[0098] Example 6: The electrostatic aerosol partitioning device according to any of the preceding examples, wherein the consecutive wall segments forming the aerosol channel are electrically insulated from each other, preferably by ring shaped segments formed from electrically non-conductive material such as synthetic polymer of ceramic material.

[0099] Example 7: The electrostatic aerosol partitioning device according to any of the preceding examples, wherein the aerosol outlet portion is connected to a flow generator configured to generate a controlled gas flow through the electrostatic aerosol partitioning device.

[0100] Example 8: The electrostatic aerosol partitioning device according to any of the preceding examples, wherein the aerosol channel has a total length of between 2 and 50 centimeters, preferably wherein the aerosol channel has a total length of between 5 and 30 centimeters, and preferably wherein the aerosol channel has a total length of between 10 and 20 centimeters.

[0101] Example 9: The electrostatic aerosol partitioning device according to any of the preceding examples, wherein the aerosol channel has an inner diameter of between 1 and 10 centimeters, preferably wherein the aerosol channel has an inner diameter of between 2 and 8 centimeters, and preferably wherein the aerosol channel has an inner diameter of between 3 and 6 centimeters.

[0102] Example 10: The electrostatic aerosol partitioning device according to any of the preceding examples, wherein the aerosol channel has a varying inner diameter such as to achieve a constant flow velocity within the electrostatic aerosol partitioning device. New PCT Patent Application October 15, 2025 Philip Morris Products S.A. 46102- PCT

[0103] -13-

[0104] Example 11 : The electrostatic aerosol partitioning device according to any of the preceding examples, wherein the wall segments of the aerosol charging portion and the aerosol separation portion are of conical geometry to achieve a constant flow velocity within these portions.

[0105] Example 12: The electrostatic aerosol partitioning device according to any of the preceding examples, wherein the aerosol inlet portion is configured to be connected to an aerosol source, such as an aerosol-generating device.

[0106] Example 13: The electrostatic aerosol partitioning device according to any of the preceding examples, wherein the aerosol inlet portion comprises additionally an opening configured to be connected to an opening to the environment or to a device which is configured to generate a constant gas flow towards the opening.

[0107] Example 14: The electrostatic aerosol partitioning device according to any of the preceding examples, wherein aerosol charging portion comprises a centrally located charger electrode surrounded by a permeable grid electrode.

[0108] Example 15: The electrostatic aerosol partitioning device according to any of the preceding examples, wherein the charger electrode is a tungsten electrode configured for application of a positive electrostatic potential of more than 5 kilovolts.

[0109] Example 16: The electrostatic aerosol partitioning device according to any of the preceding examples, wherein the permeable grid electrode is configured for application of a positive electrostatic potential of up to 1 kilovolt.

[0110] Example 17: The electrostatic aerosol partitioning device according to any of the preceding examples, wherein the wall segment of the aerosol channel of the aerosol charging portion is configured to be electrically conductive.

[0111] Example 18: The electrostatic aerosol partitioning device according to any of the preceding examples, wherein the wall segment of the aerosol channel of the aerosol charging portion is configured to be gas permeable and is made of one of a woven mesh, a machined mesh, a conductive porous material such as an open-celled metal foam, a sintered metal powder and sintered metal beads.

[0112] Example 19: The electrostatic aerosol partitioning device according to any of the preceding examples, wherein the wall segment of the aerosol channel of the aerosol charging portion is electrically grounded or connected to an alternating voltage source operated at a frequency of up to 50 Hz.

[0113] Example 20: The electrostatic aerosol partitioning device according to any of the preceding examples, wherein the aerosol charging portion comprises a plurality of charger electrodes. New PCT Patent Application October 15, 2025 Philip Morris Products S.A. 46102- PCT

[0114] -14-

[0115] Example 21 : The electrostatic aerosol partitioning device according to any of the preceding examples, wherein the charger electrodes are mounted symmetrically at circumferential openings in the wall segment of the aerosol channel of the aerosol charging portion.

[0116] Example 22: The electrostatic aerosol partitioning device according to any of the preceding examples, wherein the gas sampling line of the separation portion is provided as a hollow tube that is made from an inert, electrically conductive material.

[0117] Example 23: The electrostatic aerosol partitioning device according to any of the preceding examples, wherein the inlet end of the hollow tube of the separation portion is positioned towards a downstream end portion of the separation portion.

[0118] Example 24: The electrostatic aerosol partitioning device according to any of the preceding examples, wherein the hollow tube of the separation portion is located centrally along the longitudinal axis of the aerosol channel of the electrostatic aerosol partitioning device.

[0119] Example 25: The electrostatic aerosol partitioning device according to any of the preceding examples, wherein the hollow tube of the separation portion is connected to a device, configured for generating a controlled gas flow.

[0120] Example 26: The electrostatic aerosol partitioning device according to any of the preceding examples, wherein the hollow tube of the separation portion is configured as an electrode that is electrically grounded or connected to a voltage source, configured to be able to generate a voltage of up to 5 kilovolts.

[0121] Example 27: The electrostatic aerosol partitioning device according to any of the preceding examples, wherein the wall segment of the aerosol channel of the aerosol separation portion is configured to be gas permeable and is made of one of a woven mesh, a machined mesh, a conductive porous material such as an open-celled metal foam, a sintered metal powder and sintered metal beads.

[0122] Example 28: The electrostatic aerosol partitioning device according to any of the preceding examples, wherein the wall segment of the aerosol channel of the aerosol separation portion is configured as an electrode that is electrically grounded or connected to a voltage source, configured to be able to generate a voltage of up to minus 5 kilovolts.

[0123] Example 29: The electrostatic aerosol partitioning device according to any of the preceding examples, wherein at least a part of the aerosol channel is surrounded by a second wall.

[0124] Example 30: The electrostatic aerosol partitioning device according to any of the preceding examples, wherein the second wall is made of an insulating and gas-impermeable material. New PCT Patent Application October 15, 2025 Philip Morris Products S.A. 46102- PCT

[0125] -15-

[0126] Example 31 : The electrostatic aerosol partitioning device according to any of the preceding examples, wherein between the aerosol channel and the second wall a screen flow chamber is formed.

[0127] Example 32: The electrostatic aerosol partitioning device according to any of the preceding examples, wherein the screen flow chamber is connected to a pumping device configured to generate a controlled gas flow out of the screen flow chamber.

[0128] Example 33: A method of electrostatically partitioning an aerosol, comprising:

[0129] Introducing an aerosol into an aerosol inlet portion of an electrostatic aerosol partitioning device; charging particles comprised in the aerosol in an aerosol charging portion; generating in an aerosol separation portion an electrostatic field acting on the charged particles to separate the charged particles from the aerosol and to create a particle depleted aerosol; providing a gas sampling line in the separation portion and establishing through the gas sampling line an anisoaxial gas flow with respect to the flow direction of the aerosol through the aerosol separation portion to sample a gas phase of the particle depleted aerosol.

[0130] Example 34: The method according to any of the preceding method examples, comprising using the electrostatic aerosol partitioning device according to any one of examples 1 to 33.

[0131] Example 35: The method according to any of the preceding method examples, comprising generating a controlled gas flow through the electrostatic aerosol partitioning device with a gas flow generator.

[0132] Example 36: The method according to any of the preceding method examples, wherein the volume flow rate of the aerosol entering the inlet portion of the electrostatic aerosol partitioning device corresponds to the sum of the volume flow rate QO exiting the device through the aerosol outlet, the volume flow rate QS exiting the device through the screen flow chamber and the volume flow rate QG exiting the device via the gas sampling line.

[0133] Example 37: The method according to any of the preceding method examples, wherein the volume flow rate QO is about a magnitude larger than the volume flow rate QS and wherein the volume flow rate QS is about one to two magnitudes larger than volume flow rate QG.

[0134] Features described in relation to one embodiment may equally be applied to other embodiments of the invention.

[0135] The invention will be further described, by way of example only, with reference to the accompanying drawings in which: New PCT Patent Application October 15, 2025 Philip Morris Products S.A. 46102- PCT

[0136] -16-

[0137] Fig. 1 shows a prior art electrostatic aerosol partitioning device;

[0138] Fig. 2 shows an electrostatic aerosol partitioning device with vertical setup;

[0139] Fig. 3 shows the operation principles of the device of Fig. 2;

[0140] Fig. 4 shows computational results;

[0141] Fig. 5 shows an electrostatic aerosol partitioning device with plural charger electrodes; and

[0142] Fig. 6 shows an electrostatic aerosol partitioning device with horizontal setup.

[0143] Fig. 1 shows a prior art electrostatic aerosol partitioning device 10 comprising an aerosol inlet portion12, an aerosol charging portion 14, an aerosol separation portion 16, and a flow splitter 18. The aerosol 28 is led into the device at the aerosol inlet portion 12 and is guided through the device 10 in an annular space 26 defined between an outer cylindrical wall 20 and an inner cylindrical wall 22.

[0144] In the aerosol charging portion 14 there is provided a corona discharger formed by an axially extending corona wire 32 within a cylindrically shaped permeable grid electrode 24. The corona discharger produces ions, which are transported through openings in permeable grid electrode 24 to interact with and electrically charge aerosol particles within an aerosol charging zone 30.

[0145] After passing through charging zone 30, aerosol 28 enters the annular space 26 of aerosol separation portion 16. Inner wall 22 serves as a first electrode and outer wall 20 serves as a second electrode of aerosol separation portion 16. These electrodes are used to produce a radially outward directed electrostatic field. Charged particles in the aerosol 28 are deflected by the electrostatic field and are transported towards outer wall 20. Accordingly, in the annular aerosol flow there is formed a particle enriched flow portion close to the outer wall and a particle depleted flow portion close to the inner wall.

[0146] Flow splitter 18 physically separates the particle depleted aerosol portion from the particle enriched aerosol portion. The particle depleted aerosol portion, which corresponds to the gas sample of the present invention, may then be analyzed using differential particulate mass monitor or other similar devices. As can be seen from the setup depicted in Fig. 1 , in this prior art device the gas sampling is performed isoaxially. The sample flow is parallel to and in the same direction as the flow direction of the aerosol into the aerosol separation portion 16.

[0147] Fig. 2 shows a side cross-sectional view of an electrostatic aerosol partitioning device 100 according to the present invention. The device 100 comprises, an aerosol inlet portion 110, an aerosol charging portion 120, an aerosol separation portion 140 and an aerosol outlet portion 160. New PCT Patent Application October 15, 2025 Philip Morris Products S.A. 46102- PCT

[0148] -17-

[0149] The electrostatic aerosol partitioning device 100 further comprises a housing 102. The housing 102 defines a vertical aerosol channel 104 extending from the aerosol inlet portion 110, through the aerosol charging portion 130 and the aerosol separation portion 150 towards the aerosol outlet portion 160. As indicated by the various cross-sectional views depicted at the right-hand side of Fig. 2, the housing 102 and the vertical aerosol channel 104 are cylindrical with a circular cross-section.

[0150] The aerosol channel 104 is formed from consecutive wall segments 114, 124, 144, 162 of the aerosol inlet portion 110, the aerosol charging portion 120, the aerosol separation portion 140 and the aerosol outlet portion 160.

[0151] The aerosol inlet portion 110 is electrically grounded and is connected to an aerosol source 106 such as an electrically operated aerosol-generating device. The aerosol inlet portion 110 comprises a housing portion 112 and a cylindrical wall segment 114, which forms the inlet end of the aerosol channel 104. In this way an aerosol from the aerosol source 106 can be fed to the aerosol channel 104 of the electrostatic aerosol partitioning device 100. In order to be able to allow for a constant and pre-defined gas flow through the aerosol channel 104, opening 116 is provided at the aerosol inlet portion 110. Through this opening 116 excess aerosol from the aerosol source 106 can be ventilated. Opening 116 may also be configured to be connectable to a device able of generating a constant gas flow towards the opening 116 to maintain a sufficiently high gas flow through the aerosol channel 104.

[0152] Downstream from and directly adjacent to the aerosol inlet portion 110 there is provided the aerosol charging portion 120. The aerosol charging portion 120 comprises an outer housing portion 122, a wall segment 124 forming a part of the aerosol channel 104 and a charger electrode 126.

[0153] The charger electrode 126 is centrally located within the aerosol charging portion 120. The charger electrode 126 is configured as a corona discharger and is provided in the form of a longitudinally arranged tungsten electrode. The charger electrode 126 is configured to be connected via wiring 128 to a voltage source 130. The voltage source 130 is configured to generate a positive electrostatic potential of more than 5 kilovolts. By application of a voltage of above 5 kilovolts, a high concentration of ions is generated that may interact with the aerosol guided within the aerosol channel 104.

[0154] The charger electrode 126 is surrounded by a permeable grid electrode 132. The permeable grid electrode 132 is also connected to voltage source 130 and is configured for application of a positive electrostatic potential of up to 1 kilovolt.

[0155] As depicted in the uppermost cross-sectional view on the right-hand side of Fig. 2 the charger electrode 126 and the permeable grid electrode is mounted in the center of the aerosol channel 104 by three spokes 138 symmetrically arranged within the aerosol channel 104. New PCT Patent Application October 15, 2025 Philip Morris Products S.A. 46102- PCT

[0156] -18-

[0157] The wall segment 124 of the aerosol channel 104 of the aerosol charging portion 120 is electrically conductive and porous. In the depicted embodiment the wall segment 124 is an open-celled metal foam material. The wall segment 124 is electrically grounded and is electrically insulated from the adjacent wall segments by ring shaped insulating wall elements 134, 136 made from ceramic material.

[0158] A screen flow chamber 137 is formed between the outer housing portion 122 and the outer surface of wall segment 124. This screen flow chamber 137 is in fluid connection with a corresponding screen flow chamber 157 formed at the aerosol separation portion 140 and is configured to be connected to a pumping device 159. Particulate material condensed and / or adsorbed at the porous material of the wall segment 124 of the aerosol channel 104 of the aerosol charging portion 120 may be transported into the screen flow chamber 137 and may be removed from the device 100 by the pumping device 159.

[0159] Downstream from and directly adjacent to the aerosol charging portion 120 there is provided the aerosol separation portion 140. The aerosol separation portion 140 comprises an outer housing portion 142, a wall segment 144 forming a part of the aerosol channel 104 and a tube-shaped gas sampling line 146.

[0160] The tube-shaped gas sampling line 146 is made from electrically conductive material and forms a first electrode 148. The first electrode 148 is configured to be connected to a voltage source 150. As depicted in the middle cross-sectional view on the right-hand side of Fig. 2 the tube-shaped gas sampling line 146 forming the first electrode 148 is mounted in the center of the aerosol channel 104 by three spokes 154 symmetrically arranged within the aerosol channel 104.

[0161] The second electrode 156 of the aerosol separation portion 140 is formed by the wall segments 144 forming the aerosol channel 104 of the aerosol separation portion 140. The wall segment 144 of the aerosol channel 104 of the aerosol separation portion 140 is configured electrically conductive and porous. In the depicted embodiment the wall segment 144 is an open-celled metal foam material. The wall segment 144 is electrically connected to voltage source 158 and is electrically insulated from the adjacent wall segments by ring shaped insulating wall elements 136 and 155 made from ceramic material.

[0162] By applying an electrostatic field between the two electrodes 148, 156 of the aerosol separation portion 140, positively charged aerosol particles suspended in the aerosol are redirected towards the second electrode 156 and are captured at the wall segments 144 of the aerosol separation portion 140. In this way, the zone close to the first electrode 148 becomes depleted of charged particles, while the periphery of the aerosol channel 104 in vicinity of the second electrode 156 may become enriched in particles. New PCT Patent Application October 15, 2025 Philip Morris Products S.A. 46102- PCT

[0163] -19-

[0164] The tubular gas sampling line 146 is further configured to allow to take representative samples of the gaseous aerosol constituents in the aerosol separation portion 140. For this purpose, the inlet of the gas sampling line 146 is provided in a lower domain of the aerosol separation portion 140.

[0165] The gas sampling line 146 of the separation portion 140 is connected to a pumping device 152 that is configured for generating a controlled gas flow through the gas sampling line 146.

[0166] The gas sampling line 146 is configured co-axially with the longitudinal axis of the electrostatic aerosol partitioning device 100 and in particular with the longitudinal axis of the aerosol separation portion 140. The flow direction of the gas sampling line 146 is opposite to the entry flow direction of the aerosol into the aerosol separation portion 140. Accordingly, the gas sampling line 146 is configured to establish an anisoaxial gas flow with respect to the entry flow direction of the aerosol into the aerosol separation portion 140.

[0167] By sampling the particle depleted gas phase anisoaxially the likelihood to sample undesired particles is further reduced. Suspended articles, in particular large particles, have a tendency to follow their inertial momentum and to therefore follow a linear trajectory. By sampling the gas phase in an anisoaxial direction uncharged particles may therefore still be removed and excluded from the sampling flow. Accordingly, more precise results regarding the composition of the gas phase of the aerosol may be obtained as compared to what is achievable with existing aerosol partitioning devices.

[0168] A screen flow chamber 157 is formed between the outer housing portion 142 and the outer surface of wall segment 144. As mentioned above, this screen flow chamber 157 is in fluid connection with a corresponding screen flow chamber 137 formed at the aerosol charging portion 120 and is configured to be connected to a pumping device 159. Particulate material condensed and / or adsorbed at the porous material of the wall segment 144 of the aerosol channel 104 of the aerosol separation portion 140 may be transported into the screen flow chamber 157 and may be removed from the device 100 by the pumping device 159.

[0169] The second wall or outer housing portion 142 is made of a plastic material, which is electrically insulating and gas-impermeable. Particles that have condensed at the wall segment 124 of the aerosol channel 104 of the aerosol charging portion 120 and / or the wall segment 144 of the aerosol separation portion 140 may be absorbed by the porous material of the respective wall segments 124,144. The adsorbed material may be transported through the porous wall elements 124,144 and may re-evaporate into the screen flow chamber 137, 157. This re-evaporated material may then be pumped out of the screen flow chamber 137, 157 via the pumping device 159. In this way, material that condenses at the wall segments 124, 144 of the aerosol channel 104 may be efficiently removed from the system. New PCT Patent Application October 15, 2025 Philip Morris Products S.A. 46102- PCT

[0170] -20-

[0171] Downstream from the aerosol separation portion 140 there is provided an aerosol outlet portion 160 of the electrostatic aerosol partitioning device 100. The aerosol outlet portion 160 comprises a wall segment 162 that is made from electrically conductive material and which is electrically grounded. The wall segment 162 is electrically insulated from the wall segment 144 of the aerosol separation portion 140 by ring-shaped insulation element 155, which is made from ceramic material.

[0172] The aerosol outlet portion 160 is fluidly connected to a flow generator 166. The flow generator 166 is configured to generate a controlled gas flow through the electrostatic aerosol partitioning device 100. Thereby well-defined sampling conditions may be achieved, which allow comparability and reliable analysis of the sampling results.

[0173] The aerosol channel 104 has a total length of 20 centimeters and an essentially constant inner diameter of about 4 centimeters. For simplicity, Fig. 2 shows an electrostatic aerosol partitioning device 100 with an aerosol channel 104 having a constant inner diameter. However, the inner diameter of the aerosol channel 104 may be configured to vary in order to achieve a constant flow velocity within the electrostatic aerosol partitioning device 100. For instance, a widening around the charger electrode 126 may be included to compensate for the volume of the charger electrode 126 and hence to avoid increased aerosol flow velocities in this domain.

[0174] Details of the operation of the electrostatic aerosol partitioning device 100 are described with the scheme of Fig. 3. The electrostatic aerosol partitioning device 100 as described above is vertically oriented and aerosol with a volume flow rate is supplied from an aerosol source 106 to the aerosol inlet portion 102. Aerosol flow through the electrostatic aerosol partitioning device 100 is driven by flow generator 166, which generates a volume flow rate QQ and is connected to the aerosol outlet portion 160 of the electrostatic aerosol partitioning device 100. Pumping device 159, which generates a volume flow rate Qg is connected to the screen flow chamber 157. Pumping device 152, which generates a volume flow rate QQ, is connected to the gas phase sampling line 146. The gas sampling line 146 is again formed by the tubular element, which also forms the first electrode 148 within the aerosol separation zone 140.

[0175] Only a part of the supplied aerosol indicated as volume flow rate Q Device 'ssampled into the inlet of the aerosol channel 104, while the remaining part of the supplied aerosol is discarded via opening 106 to the environment.

[0176] The volume flow rate Qoevice that is actually fed into the aerosol channel 104 can be determined from the following equation: New PCT Patent Application October 15, 2025 Philip Morris Products S.A. 46102- PCT

[0177] -21-

[0178] QDevice = QQ + Qs+QG

[0179] The aerosol from the aerosol source 106 comprises liquid and solid particles (open circles) that are suspended in a gas phase. The aerosol that enters into the aerosol channel 104 is guided through the aerosol charging portion 120 and past the charger electrode 126. The charger electrode 126 generates positively charged ions (small black dots) that distribute throughout the aerosol charging portion 120. Aerosol particles capture these positively charged ions and itself become electrically charged (full circles).

[0180] The aerosol with the charged aerosol particles follows the gas stream towards the aerosol separation portion 140. In the aerosol separation portion 140 a radially oriented electrical field E is applied between first electrode 148 and the second electrode 144. The electrical field E results in coulomb forces in the direction of the field acting on the charged aerosol particles.

[0181] The charged aerosol particles are deflected towards the second electrode 144 formed at the wall segment 144 of the aerosol channel 104 in the aerosol separation portion 140.

[0182] The area close to the first electrode 148 becomes depleted of charged particles. The aerosol zone in close proximity to the second electrode 156 located on the channel wall segment 144 becomes enriched in particles. Particles that did not acquire any electrical charge (open circles) are unaffected by the electrical field E and follow the gas flow through the electrostatic aerosol partitioning device 100.

[0183] All particles, but particularly the charged particles, may deposit on the second electrode 156 or essentially on any wall segment of the aerosol channel 104. Such material does not reevaporate but is conveyed through the porous material of the wall segments 124, 144 into the screen flow chamber 157. The pumping device 159 connected to the screen flow chamber 157 assists in removing such material permanently from the electrostatic aerosol partitioning device 100.

[0184] As indicated above, pump 152 is attached to the gas sampling line 146 and generates a volume flow rate QQ to sample the particle depleted gas phase reaching the tip of the first electrode 148 which is at the same time the inlet of the gas sampling line 146.

[0185] Since gas flow rate QQ is very low compared to the flow rates Q / and QQ and since the gas sampling line 146 points in the opposite direction as compared to the aerosol flow through the aerosol separation portion 140, sampling of such residual particles is of low efficiency, and is even further decreased for larger particles having relevant inertial momentum. New PCT Patent Application October 15, 2025 Philip Morris Products S.A. 46102- PCT

[0186] -22-

[0187] The gas phase sampled through the gas sampling line 146 can be directly fed to a mass spectrometer 170, if suitable coupled to a gas chromatograph, for immediate compound quantification and identification.

[0188] Excess aerosol leaves the device through the aerosol outlet portion 160 and is discarded.

[0189] Computational predictions of the aspiration efficiencies (y-axis) are shown in the diagrams of Fig. 4 as functions of particle size (x-axis), electrostatic potential difference in the aerosol separation portion and volume flowrate QQ. In establishing the diagrams the following assumptions were made regarding the dimensional parameters of the electrostatic aerosol partitioning device. The inner diameter of the gas sampling line was set to 1 millimeter and the outer diameter of the gas sampling line was set to 2 millimeters. The inner diameter of the second electrode was set to 15 millimeters. All particles were considered to be charged. The gas sampling flow rate QQ was set at a constant value of 0.06 cubic centimeter per second.

[0190] The particle size is in each of the diagrams ranges between 0.05 to 5 micrometers.

[0191] In each diagram three curves are depicted, which correspond to varying volume flow rate QQ of 3 cubic centimeter per second, 7.5 cubic centimeter per second and 15 cubic centimeter per second, respectively.

[0192] The electrostatic potential difference in the aerosol separation portion was set to 0 volts (upper diagram), at 4 volts (middle diagram) and at 8 volts (lower diagram), respectively.

[0193] As can be seen from the diagrams, aspiration efficiency is close to 100 percent for all flow rates and particle sizes in the upper diagram, where no electrostatic potential difference was used in the aerosol separation portion.

[0194] At a moderate electrostatic potential of 4 volts the aspiration efficiency is close to 0 percent for small aerosol flow rates QQ of 3 cubic centimeter per second, but at only around 50 percent for higher aerosol flow rates QQ of 15 cubic centimeter per second.

[0195] At a high electrostatic potential of 8 volts the aspiration efficiency approaches 0 percent for smaller aerosol flow rates QQ of 3 cubic centimeter per second and 7.5 cubic centimeter per second, and is also well below 30 percent for higher aerosol flow rates QO of 15 cubic centimeter per second.

[0196] In all diagrams aspiration efficiency is highest for medium size particles. Thus, a strong dependency of the electrostatic potential difference, the flow rate QQ and the particle size is observed.

[0197] In Fig. 5 a cross-sectional view of an aerosol charging portion 120 of a modified electrostatic aerosol partitioning device 100 is depicted. In this embodiment, the centrally located charger electrode 126 is replaced by a plurality of circumferentially disposed charger New PCT Patent Application October 15, 2025 Philip Morris Products S.A. 46102- PCT

[0198] -23- electrodes 126. The charger electrodes 126 are mounted symmetrically at circumferential openings in the wall segment 124 of the aerosol channel 104 of the aerosol charging portion 120. The charger electrodes 126 are mounted outside of the aerosol channel 104 on the outer wall of the housing 102. The charger electrodes 126 project through the screen flow chamber 137. Operation of these charger electrodes 126 is analogous to the operation of using a single charger electrode 126 as depicted in the embodiment of Fig. 2.

[0199] In Fig. 6 a further modification of an electrostatic aerosol partitioning device 100 is depicted. This embodiment is configured for horizontal operation. For certain applications, feeding aerosol to the electrostatic aerosol partitioning device 100 in a vertical direction may not be feasible. This may be true for instance for an aerosol source 106 that can only be operated in a horizontal orientation and when angles in the aerosol flow path upstream of the electrostatic aerosol partitioning device 100 may not be desired.

[0200] Analogously to the embodiment described with regard to Fig. 2 above, the electrostatic aerosol partitioning device 100 comprises an aerosol inlet portion 110, an aerosol charging portion 120, an aerosol separation portion 140 and an aerosol outlet portion 160. An aerosol channel 104 extends through the length of the electrostatic aerosol partitioning device 100.

[0201] In this case, the aerosol channel 104 is of rectangular cross-sectional shape having an essentially constant cross-sectional area. A screen flow chamber 157 is provided to surround the aerosol channel 104 of the aerosol charging portion 120 and the aerosol separation portion 140.

[0202] The operational principle of this electrostatic aerosol partitioning device 100 is identical to the electrostatic aerosol partitioning device 100 of Fig. 2.

[0203] In the aerosol separation portion 140 the upper wall segment 144a of the aerosol channel 104 is designed as the first electrode 148. This first electrode 148 is connected to a voltage source 150 able of generating a pre-defined electrostatic potential.

[0204] The lower wall segment 144b of the aerosol channel 104 of the aerosol separation portion 140 forms the second electrode 156. The second electrode 156 is electrically connected to voltage source 158. Both electrodes 148, 156 are formed from conductive porous material. In this case these electrodes 148, 156 are formed from sintered metal powder.

[0205] Any other wall segments of the aerosol channel 104 of the aerosol separation portion 140 are manufactured from an electrically non-conductive porous material such as an open- celled ceramic material.

[0206] As depicted in the cross-sectional views of Fig. 6, the gas sampling line 146 is provided in close proximity to the first electrode 148 at the upper wall segment 144a of the aerosol separation portion 140. The gas sampling line 146 is oriented along the middle longitudinal axis of the aerosol channel 104 and can be accessed from outside the screen flow chamber New PCT Patent Application October 15, 2025 Philip Morris Products S.A. 46102- PCT

[0207] -24-

[0208] 157. The gas sampling line 146 is connected to a pumping device 152 able of generating a controlled gas flow QQ.

Claims

New PCT Patent Application October 15, 2025 Philip Morris Products S.A. 46102- PCT-25-CLAIMS1. An electrostatic aerosol partitioning device comprising: an aerosol inlet portion for introduction of an aerosol into the electrostatic aerosol partitioning device; an aerosol charging portion for charging the particles comprised in the aerosol; an aerosol separation portion configured to generate an electrostatic field acting on the charged particles to separate the charged particles from the aerosol, wherein a gas sampling line is provided in the separation portion and wherein the gas sampling line is configured to establish an anisoaxial gas flow with respect to the entry flow direction of the aerosol into the aerosol separation portion, wherein an aerosol channel is formed from consecutive wall segments of the aerosol inlet portion, the aerosol charging portion, the aerosol separation portion and an aerosol outlet portion, and wherein the wall segment of the aerosol channel of the aerosol charging portion is configured to be gas permeable and is made of one of a woven mesh, a machined mesh, a conductive porous material such as an open-celled metal foam, a sintered metal powder and sintered metal beads.

2. The electrostatic aerosol partitioning device according to claim 1 , wherein the consecutive wall segments forming the aerosol channel are electrically insulated from each other, preferably by ring shaped segments formed from electrically non-conductive material such as synthetic polymer of ceramic material.

3. The electrostatic aerosol partitioning device according to any of the preceding claims, wherein the aerosol outlet portion is connected to a flow generator configured to generate a controlled gas flow through the electrostatic aerosol partitioning device.

4. The electrostatic aerosol partitioning device according to any of the preceding claims, wherein the aerosol inlet portion is configured to be connected to an aerosol source, such as an aerosol-generating device.

5. The electrostatic aerosol partitioning device according to any of the preceding claims, wherein the aerosol charging portion comprises a centrally located charger electrode surrounded by a permeable grid electrode.New PCT Patent Application October 15, 2025 Philip Morris Products S.A. 46102- PCT-26-6. The electrostatic aerosol partitioning device according to any of the preceding claims, wherein the gas sampling line of the separation portion is provided as a hollow tube that is made from an inert, electrically conductive material.

7. The electrostatic aerosol partitioning device according to claim 6, wherein the inlet end of the hollow tube of the gas sampling line of the separation portion is positioned towards a downstream end portion of the separation portion.

8. The electrostatic aerosol partitioning device according to any of the preceding claims, wherein the gas sampling line of the separation portion is connected to a device, configured for generating a controlled gas flow.

9. The electrostatic aerosol partitioning device according to any of the preceding claims, wherein the hollow tube of the separation portion is configured as an electrode that is electrically grounded or connected to a voltage source, configured to be able to generate a voltage of up to 5 kilovolts.

10. The electrostatic aerosol partitioning device according to any of the preceding claims, wherein the wall segment of the aerosol channel of the aerosol separation portion is configured to be gas permeable and is made of one of a woven mesh, a machined mesh, a conductive porous material such as an open-celled metal foam, a sintered metal powder and sintered metal beads.

11. The electrostatic aerosol partitioning device according to any of the preceding claims, wherein at least a part of the aerosol channel is surrounded by a second wall and wherein between the aerosol channel and the second wall a screen flow chamber is formed.

12. A method of electrostatically partitioning an aerosol, comprising:Introducing an aerosol into an aerosol inlet portion of an electrostatic aerosol partitioning device; charging particles comprised in the aerosol in an aerosol charging portion; generating in an aerosol separation portion an electrostatic field acting on the charged particles to separate the charged particles from the aerosol and to create a particle depleted aerosol;New PCT Patent Application October 15, 2025 Philip Morris Products S.A. 46102- PCT-27- providing a gas sampling line in the separation portion and establishing through the gas sampling line an anisoaxial gas flow with respect to the flow direction of the aerosol through the aerosol separation portion to sample a gas phase of the particle depleted aerosol, wherein an aerosol channel is formed from consecutive wall segments of the aerosol inlet portion, the aerosol charging portion, the aerosol separation portion and an aerosol outlet portion, wherein the wall segment of the aerosol channel of the aerosol charging portion is configured to be gas permeable and is made of one of a woven mesh, a machined mesh, a conductive porous material such as an open-celled metal foam, a sintered metal powder and sintered metal beads.

13. The method according to claim 12, wherein at least a part of the aerosol channel is surrounded by a second wall and wherein between the aerosol channel and the second wall a screen flow chamber is formed.

14. The method according to claim 13, wherein the volume flow rate of the aerosol entering the inlet portion of the electrostatic aerosol partitioning device corresponds to the sum of the volume flow rate Qo exiting the device through the aerosol outlet, the volume flow rate Qs exiting the device through the screen flow chamber and the volume flow rate QG exiting the device via the gas sampling line.

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