Smoking substitute apparatus
A smoking substitute apparatus for generating an aerosol, comprising: an air inlet and an outlet; a passage extending between the air inlet and the outlet, air flowing in use along the passage for inhalation by a user drawing on the apparatus; and an aerosol generation chamber containing an aerosol generator being operable to generate an aerosol from an aerosol precursor; wherein the aerosol generation chamber comprises at least one chamber outlet in fluid communication with the passage at a junction, the at least one chamber outlet permitting, in use, aerosol generated by the aerosol generator to be entrained into an air flow along the passage; and wherein the passage has a constriction configured to induce, in use, a localized reduced pressure in the air flow at the junction for drawing out the aerosol from the aerosol generation chamber.
1 . A smoking substitute apparatus for generating an aerosol, comprising:
an air inlet and an outlet;
a passage extending between the air inlet and the outlet, air flowing in use along the passage for inhalation by a user drawing on the smoking substitute apparatus; and
an aerosol generation chamber containing an aerosol generator being operable to generate an aerosol from an aerosol precursor;
wherein the aerosol generation chamber comprises at least one chamber outlet in fluid communication with the passage at a junction, the at least one chamber outlet permitting, in use, aerosol generated by the aerosol generator to be entrained into an air flow along the passage;
wherein the passage has a constriction at or adjacent the junction, wherein a hydraulic diameter of the passage at or adjacent to said junction is smaller than a portion of the passage immediately upstream of the junction in a direction of the air flow, the constriction being configured to induce, in use, a localized reduced pressure in the air flow at the junction for drawing out the aerosol from the aerosol generation chamber; and
wherein the at least one chamber outlet is positioned adjacent to the passage and opens in a direction of the air flow in the passage at the junction.
2 . The smoking substitute apparatus of claim 1 , wherein the constriction comprises one or more of a venturi tube, an orifice plate, and a narrowed section along the passage.
3 . The smoking substitute apparatus of claim 1 , wherein the aerosol generation chamber is substantially sealed against air flow except for the at least one chamber outlet.
4 . The smoking substitute apparatus of claim 1 , wherein the direction of the air flow is a first direction, wherein the junction is configured to be in fluid communication with the at least one chamber outlet through a junction inlet, and wherein said junction inlet opens towards a second direction substantially orthogonal to the first direction of the air flow at the junction.
5 . The smoking substitute apparatus of claim 1 , wherein the passage is arranged to allow all of the air flow entering the smoking substitute apparatus through the air inlet to bypass the aerosol generation chamber.
6 . The smoking substitute apparatus of claim 1 , wherein the at least one chamber outlet is closed by a one way valve.
7 . The smoking substitute apparatus of claim 1 , wherein the aerosol precursor comprises a liquid aerosol precursor, and wherein the aerosol generator comprises a heater configured to generate the aerosol by vaporizing the liquid aerosol precursor.
8 . The smoking substitute apparatus of claim 7 , further comprising a tank for storing a reservoir of the liquid aerosol precursor, and wherein the tank is spaced from the aerosol generation chamber and is arranged to be in fluid communication with a wick of the heater through a liquid conduit.
9 . The smoking substitute apparatus of claim 8 , wherein the hydraulic diameter of the passage is a first hydraulic diameter, and wherein the liquid conduit has a second hydraulic diameter ranging from 0.01 mm to 10 mm for controlling a flow rate of the aerosol precursor from the tank towards the wick.
10 . The smoking substitute apparatus of claim 1 , wherein the aerosol generation chamber is configured to have an internal volume ranging between 68 mm 3 to 680 mm 3 and/or a length ranging between 2 mm to 20 mm.
11 . The smoking substitute apparatus of claim 1 , wherein the smoking substitute apparatus is configured to generate the aerosol having a mean droplet size, d 50 , of at least 1 μm.
12 . The smoking substitute apparatus of claim 1 , wherein the hydraulic diameter of the passage is a first hydraulic diameter, wherein the portion of the passage immediately upstream of the junction in the direction of the air flow is an expanded portion, and wherein the expanded portion has a second hydraulic diameter that is larger than the first hydraulic diameter of the passage immediately upstream of the expanded portion.
13 . A smoking substitute system for generating an aerosol, comprising:
i) a smoking substitute apparatus, comprising:
an air inlet and an outlet;
a passage extending between the air inlet and the outlet, air flowing in use along the passage for inhalation by a user drawing on the smoking substitute apparatus; and
an aerosol generation chamber containing an aerosol generator being operable to generate an aerosol from an aerosol precursor;
wherein the aerosol generation chamber comprises at least one chamber outlet in fluid communication with the passage at a junction, the at least one chamber outlet permitting, in use, aerosol generated by the aerosol generator to be entrained into an air flow along the passage;
wherein the passage has a constriction at or adjacent the junction, wherein a hydraulic diameter of the passage at or adjacent to said junction is smaller than a portion of the passage immediately upstream of the junction in a direction of the air flow, the constriction being configured to induce, in use, a localized reduced pressure in the air flow at the junction for drawing out the aerosol from the aerosol generation chamber; and
wherein the at least one chamber outlet is positioned adjacent to the passage and opens in a direction of the air flow in the passage at the junction; and
ii) a main body configured to engage with the smoking substitute apparatus; wherein the main body comprises a controller and a power source configured to energize the aerosol generator.
14 . The smoking substitute system of claim 13 , wherein the hydraulic diameter of the passage is a first hydraulic diameter, wherein the portion of the passage immediately upstream of the junction in the direction of the air flow is an expanded portion, and wherein the expanded portion has a second hydraulic diameter that is larger than the first hydraulic diameter of the passage immediately upstream of the expanded portion.
15 . A method of using a smoking substitute apparatus, the smoking substitute apparatus comprising:
an air inlet and an outlet;
a passage extending between the air inlet and the outlet, air flowing in use along the passage for inhalation by a user drawing on the smoking substitute apparatus; and
an aerosol generation chamber containing an aerosol generator being operable to generate an aerosol from an aerosol precursor;
wherein the aerosol generation chamber comprises at least one chamber outlet in fluid communication with the passage at a junction, the at least one chamber outlet permitting, in use, aerosol generated by the aerosol generator to be entrained into an air flow along the passage;
wherein the passage has a constriction at or adjacent the junction, wherein a hydraulic diameter of the passage at or adjacent to said junction is smaller than a portion of the passage immediately upstream of the junction in a direction of the air flow, the constriction being configured to induce, in use, a localized reduced pressure in the air flow at the junction for drawing out the aerosol from the aerosol generation chamber, and
wherein the at least one chamber outlet is positioned adjacent to the passage and opens in a direction of the air flow in the passage at the junction;
the method comprising steps:
i) generating the aerosol with the aerosol generator; and
ii) drawing on the smoking substitute apparatus to induce a localized pressure drop in the air flow at the junction, so as to draw out the generated aerosol from the aerosol generation chamber.
16 . The method of claim 15 , wherein the hydraulic diameter of the passage is a first hydraulic diameter, wherein the portion of the passage of the smoking substitute apparatus immediately upstream of the junction in the direction of the air flow is an expanded portion, and wherein the expanded portion has a second hydraulic diameter that is larger than the first hydraulic diameter of the passage immediately upstream of the expanded portion.