ELECTRICALLY OPERATED AEROSOL GENERATING SYSTEM HAVING AEROSOL PRODUCTION CONTROL

• US 20140321837A1
• Filed: 10/25/2012
• Published: 10/30/2014
• Est. Priority Date: 10/27/2011
• Status: Active Grant

• Current Assignee: Philip Morris Products SA (Philip Morris Limited)
• Original Assignee: Philip Morris Products SA (Philip Morris Limited)
• Inventors: Flick, Jean-Marc
• Granted Patent: US 10,247,443 B2
• Time in Patent Office: Days
• US Class Current: 392/387
• CPC Class Codes: A24F 40/10 Devices using liquid inhalable precursors
• CPC Class Codes: A24F 40/51 Arrangement of sensors
• CPC Class Codes: A61M 11/042 electrical
• CPC Class Codes: A61M 15/06 Inhaling appliances shaped like cigars, cigarettes or pipes
• CPC Class Codes: A61M 2016/0024 with an on-off output signal, e.g. from a switch
• CPC Class Codes: A61M 2205/0211 Ceramics
• CPC Class Codes: A61M 2205/3653 by Joule effect, i.e. electric resistance
• CPC Class Codes: A61M 2205/8206 battery-operated
• CPC Class Codes: F24H 1/0018 using electric energy supply

Abstract

A method of controlling aerosol production in an aerosol-generating device is provided, the device including a powered aerosol generating element, a flow channel to allow a flow of gas past the element, and a flow sensor to detect air flow in the flow channel, the method including: determining a value of a first parameter related to a change in flow rate; and reducing a supply of power to the element depending on a comparison result between the first parameter value and a threshold value, the first parameter being derived from a combination of a second parameter that is a measure of a flow rate detected by the flow sensor and a third parameter related to the flow rate. Also provided is a method of reducing or suspending aerosol production, based not simply on a detected flow rate, but on another measure indicative of the evolution of the flow characteristics.

Claims

1. A method of controlling aerosol production in an aerosol-generating device, the device comprising:

an aerosol generating element;

a flow channel configured to allow an air flow past the aerosol generating element; and

a flow sensor configured to detect the air flow in the flow channel, the method comprising the steps of;

determining a value of a first parameter related to a change in flow rate of the air flow; and

changing the supply of power to the aerosol generating element depending on a result of a comparison between the value of the first parameter and a threshold value,

wherein the first parameter is derived from a combination of a second parameter that is a measure of a flow rate detected by the flow sensor and a third parameter related to the flow rate, and

wherein the third parameter is temperature, power supplied to the aerosol generating element, a maximum detected flow rate, or a rate of change of flow rate, or is derived from a combination of two or more of temperature, power supplied to the aerosol generating element, a maximum detected flow rate, and a rate of change of flow rate.

2. The method according to claim 1, wherein the third parameter is temperature or maximum flow rate, and the method further comprises a step of deriving the first parameter by calculating a ratio between the second and third parameters.

3. The method according to claim 1, wherein the third parameter is power supplied to the aerosol generating element or rate of change of flow rate, and the method further comprises a step of deriving the first parameter by calculating a product of the second and third parameters.

4. The method according claim 1, wherein the first parameter is a rate of change of flow rate.

5. The method according claim 1, wherein the aerosol-generating element is an electrically heated heating element, and the first parameter is proportional to a temperature of the heating element divided by a flow rate detected by the flow sensor.

6. The method according claim 1, further comprising the step of re-supplying power to the aerosol-generating element based on a flow rate detected by the flow sensor.

9. Electric circuitry for an electrically operated aerosol generating device, the electric circuitry being arranged to perform the method of claim 1.

10. A non-transitory computer readable storage medium having a computer program stored thereon which, when run on programmable electric circuitry for an electrically operated aerosol generating device, causes the programmable electric circuitry to perform the method of claim 1.

7. An electrically operated aerosol generating device, comprising:

at least one electric aerosol generating element for forming an aerosol from a substrate;

a power supply for supplying power to the at least one aerosol generating element; and

electric circuitry for controlling supply of power from the power supply to the at least one aerosol generating element, the electric circuitry including a sensor for detecting air flow past the aerosol generating element,

wherein the electric circuitry is configured to;

determine a value of a first parameter related to a change in flow rate of the air flow; and

reduce or suspend the supply of power to the aerosol generating element to zero dependent on a result of a comparison between the value of the first parameter and a threshold value,

wherein the first parameter is derived from a combination of a second parameter that is a measure of a flow rate detected by the flow sensor and a third parameter related to the flow rate, and

wherein the third parameter is temperature, power supplied to the aerosol generating element, a maximum detected flow rate, or a rate of change of flow rate, or is derived from a combination of two or more of temperature, power supplied to the aerosol generating element, a maximum detected flow rate, and a rate of change of flow rate.

8. The electrically operated aerosol generating device according to claim 8, wherein the aerosol-generating element is an electrically heated heating element and the first parameter is proportional to a temperature of the heating element divided by a flow rate detected by the flow sensor.

11. (canceled)