Smoking substitute apparatus

Abstract

A smoking substitute apparatus (150) with an air inlet; an aerosol generator for generating an aerosol from an aerosol precursor for inhalation by a user; an outlet formed at a mouthpiece; and an aerosol delivery conduit (602) extending downstream from the aerosol generator to the outlet. An air flow path extends between the air inlet and the outlet and along the aerosol delivery conduit for conveying the aerosol to the user. In operation, the aerosol generator heats the aerosol precursor to form vaporised aerosol precursor, the vaporised aerosol precursor being transported in the air flow and condensing to form aerosol droplets. The air flow path and the aerosol generator are configured to control the air flow characteristics at the aerosol generator to provide an aerosol with predetermined particle size characteristics at a first position along the air flow path in the aerosol delivery conduit. The apparatus further comprises an air flow disruptor (610) disposed in the aerosol delivery conduit (602) at or downstream of the first position, the air flow disruptor (610) causing disruption of the air flow downstream of the air flow disruptor and consequently cooling of the aerosol droplets. The air flow disruptor comprises a protrusion extending into the air flow path laterally from a side wall (612) of the aerosol delivery conduit (602). Also disclosed is a method of operation of the apparatus.

1 . A method of operating a smoking substitute apparatus, the smoking substitute apparatus comprising:
 an air inlet;   an aerosol precursor;   an aerosol generator for generating an aerosol from the aerosol precursor for inhalation by a user;   an outlet formed at a mouthpiece;   at least one air flow path between the air inlet and the outlet for conveying the aerosol to the user;   the method including the steps:   operating the aerosol generator to heat the aerosol precursor to form vaporised aerosol precursor, the vaporised aerosol precursor being transported in the air flow and condensing to form aerosol droplets,
 wherein the air flow path and the aerosol generator are configured to control the air flow characteristics at the aerosol generator such that the aerosol droplets have predetermined particle size characteristics at a first position in the air flow path downstream of the aerosol generator, the average temperature of the aerosol droplets at the first position being at least 70° C., 
 the apparatus further comprising an air flow disruptor disposed in the air flow path at or downstream of the first position, wherein the air flow disruptor is configured to disrupt the air flow downstream of the air flow disruptor such that the aerosol droplets are cooled to an average temperature at a second position in the air flow path, corresponding to the outlet formed at the mouthpiece, of not more than 60° C., and wherein the aerosol particle size characteristics are substantially the same at the first position as at the second position. 
   
     
     
         2 . A method according to  claim 1  wherein the average temperature of the aerosol droplets at the first position is at least 75° C. 
     
     
         3 . A method according to  claim 1  wherein the average temperature of the aerosol droplets at the second position is not more than 55° C. 
     
     
         4 . A method according to  claim 1  wherein the predetermined particle size characteristics of the aerosol at the first position and the second position include the characteristic that the Dv50 particle size of the aerosol is in the range 2-5 μm. 
     
     
         5 . A method according to  claim 1  wherein the apparatus is operated by a user drawing air through the apparatus in a series of inhales each of at least one second duration, and wherein a first inhale of said series takes place without a preceding inhale, or with a time delay of at least one minute from a preceding inhale, and a second inhale takes place after the first inhale and with a time delay after the end of the first inhale of not less than 10 seconds and not more than 30 seconds, and wherein the average temperature of the aerosol droplets at the second position for the second inhale is within 10° C. of the average temperature of the aerosol droplets at the second position for the first inhale. 
     
     
         6 . A method according to  claim 5  wherein the average temperature of the aerosol droplets at the second position for the second inhale is within 5° C. of the average temperature of the aerosol droplets at the second position for the first inhale. 
     
     
         7 . A smoking substitute apparatus comprising:
 an air inlet;   an aerosol precursor;   an aerosol generator for generating an aerosol from the aerosol precursor for inhalation by a user;   an outlet formed at a mouthpiece;   at least one air flow path between the air inlet and the outlet for conveying the aerosol to the user;   wherein, in operation, the aerosol generator heats the aerosol precursor to form vaporised aerosol precursor, the vaporised aerosol precursor being transported in the air flow and condensing to form aerosol droplets,
 wherein the air flow path and the aerosol generator are configured to control the air flow characteristics at the aerosol generator to such that the aerosol droplets have predetermined particle size characteristics at a first position in the air flow path downstream of the aerosol generator, the average temperature of the aerosol droplets at the first position being at least 70° C., 
 the apparatus further comprising an air flow disruptor disposed in the air flow path at or downstream of the first position, wherein the air flow disruptor is configured to disrupt the air flow downstream of the air flow disruptor such that: the aerosol droplets are cooled to an average temperature at a second position in the air flow path, corresponding to the outlet formed at the mouthpiece, of not more than 60° C., and wherein the aerosol particle size characteristics are substantially the same at the first position as at the second position. 
   
     
     
         8 . A smoking substitute apparatus according to  claim 7  wherein the average temperature of the aerosol droplets at the first position is at least 75° C. 
     
     
         9 . A smoking substitute apparatus according to  claim 7  wherein the average temperature of the aerosol droplets at the second position is not more than 55° C. 
     
     
         10 . A smoking substitute apparatus according to  claim 7  wherein the predetermined particle size characteristics of the aerosol at the first position and the second position include the characteristic that the Dv50 particle size of the aerosol is in the range 2-5 μm. 
     
     
         11 . A smoking substitute apparatus according to  claim 7  wherein the apparatus is operable by a user drawing air through the apparatus in a series of inhales each of at least one second duration, and wherein the average temperature of the aerosol droplets at the second position for a second inhale is within 10° C. of the average temperature of the aerosol droplets at the second position for a first inhale when the apparatus is operated by the user so that a first inhale of said series takes place without a preceding inhale, or with a time delay of at least one minute from a preceding inhale, and a second inhale takes place after the first inhale and with a time delay after the end of the first inhale of not less than 10 seconds and not more than 30 seconds, and wherein the average temperature of the aerosol droplets at the second position for the second puff is within 10° C. of the average temperature of the aerosol droplets at the second position for the first puff. 
     
     
         12 . A smoking substitute apparatus according to  claim 11  wherein the average temperature of the aerosol droplets at the second position for the second inhale is within 5° C. of the average temperature of the aerosol droplets at the second position for the first inhale. 
     
     
         13 . A smoking substitute apparatus according to  claim 7  wherein the aerosol generator is disposed in a vaporisation chamber within the apparatus, the air flow path between the air inlet and the outlet passing through the vaporisation chamber. 
     
     
         14 . A smoking substitute apparatus according to  claim 7  wherein the aerosol generator is disposed in a vaporisation chamber within the apparatus, the vaporisation chamber having a vaporisation chamber outlet, the air flow path between the air inlet and the outlet bypassing the vaporisation chamber and entraining aerosol particles from the vaporisation chamber outlet. 
     
     
         15 . A smoking substitute apparatus according to  claim 7  wherein the aerosol generator is disposed in a vaporisation chamber within the apparatus, the air flow path between the air inlet and the outlet passing through the vaporisation chamber, there being at least one auxiliary air inlet disposed to permit at least part of the air exiting through the outlet to be derived from the auxiliary air inlet and bypass the vaporisation chamber. 
     
     
         16 . A method according to  claim 1  wherein the air flow disruptor comprises a protrusion extending into the air flow path laterally from a side wall of an aerosol delivery conduit between the first position and the second position. 
     
     
         17 . A method according to  claim 16  wherein the air flow disruptor includes an air flow facing surface, the air flow facing surface being substantially planar and disposed obliquely to a principal axis of the aerosol delivery conduit. 
     
     
         18 . A method according to  claim 16  wherein
 the protrusion extends in a direction substantially perpendicular to a principal axis of the aerosol delivery conduit for a radial protrusion distance, and 
 an axial length of the protrusion, projected along an axial direction of the aerosol delivery conduit, is between 0.5 and 2 times the radial protrusion distance. 
 
     
     
         19 . A method according to  claim 16  wherein
 the protrusion extends in a direction substantially perpendicular to a principal axis of the aerosol delivery conduit for a radial protrusion distance, and 
 a circumferential length of the protrusion, projected along a direction around the circumference of the aerosol delivery conduit, is between 0.5 and 2 times the radial protrusion distance. 
 
     
     
         20 . A method according to  claim 16  wherein the protrusion is a blade or tab configured to partially divide the air flow in the aerosol delivery conduit.