Aerosol-generating system for generating and controlling the quantity of nicotine salt particles

Abstract

There is provided an aerosol-generating system including an aerosol-generating device in cooperation with an aerosol-generating article. The aerosol-generating article includes a first compartment including a volatile liquid; and a second compartment including a delivery enhancing compound. The aerosol-generating device includes an outer housing configured to receive the aerosol-generating article; a power supply; a heater, configured to receive power from the power supply and arranged to heat the first compartment when the aerosol-generating article is received in the outer housing; an input, configured to receive an input from a user; and a controller, configured to control an amount of power supplied to the heater in dependence on a user input, such that a quantity of volatile liquid aerosolised is determined by the user input.

Claims

1. An aerosol-generating system, comprising: an aerosol-generating device in cooperation with an aerosol-generating article; the aerosol-generating article comprising: a first compartment comprising a volatile liquid, and a second compartment comprising a delivery enhancing compound, wherein the delivery enhancing compound reacts with the volatile liquid in a vapour phase to form an aerosol to be inhaled by a user; and the aerosol-generating device comprising: an outer housing configured to receive the aerosol-generating article, a power supply, at least one heater, configured to receive power from the power supply and arranged to heat the first compartment when the aerosol-generating article is received in the outer housing, at least one further heater configured to receive power from the power supply and to heat the second compartment when the aerosol-generating article is received in the outer housing, an input, configured to receive a plurality of discrete inputs from the user, each discrete input corresponding to a respective discrete quantity of aerosolised volatile liquid required by the user, and a controller, configured to: control an amount of power supplied to the at least one heater by changing a duty cycle, each discrete input of said plurality from the user corresponding to a respective discrete duty cycle among a plurality of discrete duty cycles, such that the discrete quantity of aerosolised volatile liquid is determined by the user input, and control an amount of power supplied to the at least one further heater by changing the duty cycle, wherein the duty cycle for the amount of power supplied to the at least one heater is different than the duty cycle for the amount of power supplied to the at least one further heater, such that vapour concentrations of a quantity of aerosolised delivery enhancing compound and the discrete quantity of aerosolised volatile liquid have a reaction stoichiometry that is balanced proportionally for said each discrete input.

2. The aerosol-generating system according to claim 1, wherein the discrete duty cycles include: between about 90% and about 100%, between about 80% and about 90%, and between about 55% and about 65%.

3. The aerosol-generating system according to claim 1, wherein said each discrete duty cycle of said plurality is a steady-state portion of a respective discrete power profile among a plurality of discrete power profiles.

4. The aerosol-generating system according to claim 3, wherein each discrete power profile of said plurality comprises plural discrete duty cycles among said plurality of discrete duty cycles, including the steady-state portion.

5. The aerosol-generating system according to claim 4, wherein the plural discrete duty cycles include a first duty cycle of between about 90% and about 100%.

6. The aerosol-generating system according to claim 5, wherein at least one of the plurality of discrete power profiles comprises a second duty cycle of between about 65% and about 75%.

7. The aerosol-generating system according to claim 1, wherein the quantity of volatile liquid aerosolised is dependent on a temperature of the first compartment, the temperature of the first compartment being directly related to the amount of power supplied to the at least one heater.

8. The aerosol-generating system according to claim 1, the aerosol-generating article further comprising an insulating element between the first compartment and the second compartment.

9. The aerosol-generating system according to claim 1, further comprising at least one air inlet upstream of the first compartment, and at least one air outlet downstream of the second compartment, the at least one air inlet and the at least one air outlet being arranged to define an air flow pathway extending from the at least one air inlet to the at least one air outlet via the first compartment, and via the second compartment.

10. The aerosol-generating system according to claim 1, wherein the volatile liquid comprises nicotine, and the quantity of nicotine aerosolised per puff of the user on the aerosol-generating device is controllable between about 50 micrograms and about 150 micrograms.

11. The aerosol-generating system according to claim 1, wherein the delivery enhancing compound comprises an acid.

12. An aerosol-generating device for an aerosol-generating system, comprising: an outer housing, configured to receive an aerosol-generating article comprising a first compartment comprising a volatile liquid, and a second compartment comprising a delivery enhancing compound, wherein the delivery enhancing compound reacts with the volatile liquid in a vapour phase to form an aerosol to be inhaled by a user; a power supply; at least one heater, configured to receive power from the power supply and arranged to heat the first compartment when the aerosol-generating article is received in the outer housing; at least one further heater configured to receive power from the power supply and to heat the second compartment when the aerosol-generating article is received in the outer housing; an input, configured to receive a plurality of discrete inputs from the user, each discrete input corresponding to a respective discrete quantity of aerosolised volatile liquid required by the user; and a controller, configured to: control an amount of power supplied to the at least one heater by changing a duty cycle, each discrete input of said plurality from the user corresponding to a respective discrete duty cycle among a plurality of discrete duty cycles, such that the discrete quantity of aerosolised volatile liquid is determined by the user input, and control an amount of power supplied to the at least one further heater by changing the duty cycle, wherein the duty cycle for the amount of power supplied to the at least one heater is different than the duty cycle for the amount of power supplied to the at least one further heater, such that vapour concentrations of a quantity of aerosolised delivery enhancing compound and the discrete quantity of aerosolised volatile liquid have a reaction stoichiometry that is balanced proportionally for said each discrete input.

Description

(1) The invention will be further described, by way of example only, with reference to the accompanying drawings in which:

(2) FIG. 1(a) shows a schematic representation of an aerosol-generating system according to the present invention;

(3) FIG. 1(b) shows a schematic representation of an alternative aerosol-generating system to the present invention;

(4) FIG. 2 shows a graph of a set of three power profiles used to apply power to the heater in an aerosol-generating system according to the invention; and

(5) FIG. 3 shows a graph of a set of three temperature profiles of the first compartment of an aerosol-generating system corresponding to the power profiles shown in FIG. 2.

(6) FIG. 1(a) shows a schematic representation of an aerosol-generating system 100. The system 100 comprises an aerosol-generating device 102 and an aerosol-generating article 103. The aerosol-generating device comprises an outer housing 104, having an elongate cylindrical shape, for housing a power supply 105, an electrical heater 106, an input 107, control electronics 108, and a piercing member 110. The piercing member comprises an elongate shaft portion 112 and a piercing portion 114. The housing 104 has an elongate cylindrical cavity configured to receive the aerosol-generating article 103. The longitudinal length of the cavity is less than the length of the article 103 such that the proximal, or downstream, end of the article 103 protrudes from the cavity. The piercing member 110 is positioned centrally within the cavity of the aerosol-generating device and extends along the longitudinal axis of the cavity.

(7) Air inlets (not shown) are provided at the distal, upstream, end of the aerosol-generating device 102. Air outlets (not shown) are provided at the proximal, downstream, end of the aerosol-generating article 103.

(8) The aerosol-generating article 103 also has an elongate cylindrical shape and comprises a first compartment 118 comprising a volatile liquid nicotine source, and a second compartment 120 comprising a volatile delivery enhancing compound source. The first compartment comprises a tubular porous element, upon which is sorbed the volatile liquid nicotine source. The second compartment also comprises a tubular porous element upon which is sorbed the volatile delivery enhancing compound source.

(9) The first compartment 118 and the second compartment 120 are arranged in series and are spaced apart along the longitudinal axis of the aerosol-generating article. An insulating portion 121 is provided between the first compartment and the second compartment. The first compartment 118 is positioned at the distal, or upstream, end of the aerosol-generating article 103. The second compartment 120 is positioned downstream of the first compartment. A further element (not shown) in the form of a mouthpiece or the like may be provided at the downstream end of the second compartment.

(10) The upstream and downstream ends of the first compartment 118 and the second compartment 120 of the aerosol-generating article 103 are sealed by frangible barriers 122, 124 and 126, 128 respectively. The frangible barriers are made from metal film, such as aluminium.

(11) In use, as the aerosol-generating article 103 is inserted into the cavity of the aerosol-generating device 102 the piercing member 110 is inserted into the aerosol-generating article 103 and pierces the frangible barriers 122, 124, 126 and 128 at the upstream and downstream ends of the first compartment 118 and second compartment 120 of the aerosol-generating article 103. This allows a user to draw air into the aerosol-generating article through the air inlets at the distal, upstream, end thereof, downstream through the first compartment, and the second compartment and out of the article through the air outlets at the proximal, downstream, end thereof. The air flow pathway further extends about the shaft of the piercing member via the hole made in the frangible barrier 128 at the proximal, downstream end of the second compartment, and then about the piercing portion 114. By providing a shaft having a smaller diameter than the maximum diameter of the piercing portion, the air flow pathway is enabled to extend around the shaft in the region of the frangible barrier.

(12) Nicotine vapour is released from the volatile liquid nicotine source in the first compartment 118 into the air stream drawn through the aerosol-generating article 103. Delivery enhancing compound vapour, which in the preferred embodiment contains pyruvic acid, is released from the delivery enhancing compound sorbed on the tubular porous element of the second compartment 122 into the air stream drawn through the aerosol-generating article 103. The delivery enhancing compound vapour reacts with the nicotine vapour in the gas phase to form an aerosol, which is delivered to the user through the proximal, downstream, end of the aerosol-generating article 103.

(13) To control the quantity of nicotine vapour released from the volatile liquid nicotine source in the first compartment, the control circuitry provides a controlled power profile to the heater. The user inputs the required quantity via the input 107, and thus the controller applies the corresponding power profile. In general, each power profile comprises a steady-state duty cycle which varies in accordance with the quantity of nicotine required.

(14) FIG. 1(b) shows a schematic representation of an alternative aerosol-generating system 130. The system 130 is similar to the system 100 shown in FIG. 1(a) and like reference numerals refer to like components. The system 130 comprises an aerosol-generating device 132 and an aerosol-generating article 103. The aerosol-generating device comprises an outer housing 104, for housing a power supply 105, an electrical heater 106, an input 107, control electronics 134, and a piercing member 110. The device 132 further comprises a second heater 136 configured to heat the second compartment of the aerosol-generating article 103.

(15) Similarly to the system shown in FIG. 1(a), to control the quantity of nicotine vapour released from the volatile liquid nicotine source in the first compartment, the control circuitry 134 provides a controlled power profile to the heater 106. The user inputs the required quantity via the input 107, and thus the controller applies the corresponding power profile. In general, each power profile comprises a steady-state duty cycle which varies in accordance with the quantity of nicotine required. In addition, the control circuitry 134 provides a controlled power profile to the second heater 136 to heat the second compartment to a different temperature to that of the first compartment. In general, the controller is configured to provide less power to the second heater as compared to the first heater, and hence provides a lower duty cycle to the second heater as compared to the duty cycle provided to the first heater.

(16) FIG. 2 shows a set of three example power profiles. A first profile, A, has a single steady-state duty cycle of 95% The second profile, B, comprises two duty cycles, a first of 95%, and a second of 85%. The third profile, C, comprises three duty cycles, a first of 95%, a second of 70% and a third of 60%. The power profiles are designed to increase the temperature of the first compartment to a minimum operating temperature in as short amount of time as possible. The third power profile is configured to substantially hold the temperature of the first compartment at this minimum operating temperature. The second power profile is configured to increase the temperature further, and the first power profile is configured to increase the temperature to a maximum operating temperature. As will be appreciated, the amount of nicotine vapourised increases with increasing operating temperature.

(17) FIG. 3 shows the set, A, B and C, of temperature profiles corresponding to the power profiles A, B and C shown in FIG. 2, and were conducted at an ambient temperature of 22 degrees C. and 50% relative humidity. FIG. 3 also shows the set of temperature profiles of the second compartment for each of the power profiles, profile A corresponds to temperature profile D, profile B corresponds to temperature profile E, and profile C corresponds to temperature profile E. As can be seen, the temperature of the second compartment is substantially the same for each of the power profiles due to the insulating portion 121 of the aerosol-generating article.

(18) The first power profile, A, corresponds to an average nicotine delivery of approximately 150 micrograms per puff; averaged over a group of 12 puffs. The first power profile, B, corresponds to an average nicotine delivery of approximately 100 micrograms per puff; averaged over a group of 12 puffs. The first power profile, C, corresponds to an average nicotine delivery of approximately 50 micrograms per puff; averaged over a group of 12 puffs.

(19) It has been found that reducing the average quantity of nicotine provided in each puff increases the number of usage experiences available to the user.