Controlled Bubble Nucleation

Abstract

A heater with intentional surface aberrations spaced apart a predetermined distance allows for an efficient heating process by encouraging bubble nucleation at the sites of the aberrations. The spacing between aberrations creates a soft restriction to the size of the bubbles, which encourages a maximum bubble size. This reduces the likelihood of the creation of large bubbles that may inhibit heat transfer to the liquid. In embodiments where the liquid is a thin film over the heater, such as in ENDS applications, this structure can be used to skew droplet production to certain ranges of droplet sizes based on controlling the size of the bubbles.

1 . A heater for heating a liquid having a set of physical characteristics including a viscosity and a boiling point, the heater comprising:
 a heating surface for transferring heat into the liquid; and   first and second aberrations on the heating surface spaced apart by a distance determined in accordance with at least one of the set of physical characteristics and a heating objective.   
     
     
         2 . The heater of  claim 1  wherein the heating surface is planar. 
     
     
         3 . The heater of  claim 2  wherein the first and second aberrations are contained within a set of aberrations. 
     
     
         4 . The heater of  claim 3  wherein aberrations within the set of aberrations are spaced apart from each other by at least the determined distance. 
     
     
         5 . The heater of  claim 3  wherein the location of each aberration within the set of aberrations corresponds to the center of a circle having a radius of half the determined distance, and having a distance to the nearest next aberration of the determined distance. 
     
     
         6 . The heater of  claim 3  wherein the location of each aberration within the set of aberrations corresponds to the centre of a hexagon, and each hexagon corresponding to an aberration within the set of aberrations is tiled across the heating surface. 
     
     
         7 . The heater of  claim 1  wherein the heater is an element of a boiler. 
     
     
         8 . The heater of  claim 1  wherein at least one of the first and second aberrations is machined into the heating surface. 
     
     
         9 . The heater of  claim 1  wherein at least one of the first and second aberrations is created on the heating surface through at least one of:
 perforating the heating surface; 
 stamping the heating surface; 
 etching the heating surface; 
 forging the heating surface with at least one aberration; and 
 additively manufacturing the at least one aberration. 
 
     
     
         10 . The heater of  claim 1  wherein the heater comprises at least one of the following materials:
 aluminium; 
 copper; 
 steel; 
 titanium; and 
 nickel. 
 
     
     
         11 . The heater of  claim 1  wherein the heater is a linear heating element. 
     
     
         12 . The heater of  claim 11  wherein the heater is wound around a wick. 
     
     
         13 . The heater of  claim 12  wherein the wick comprises at least one of cotton, linen, nylon, other polymer based materials, hemp, wool, cellulose, glass fibers and carbon fibers. 
     
     
         14 . The heater of  claim 11  further comprising a third aberration, wherein the first and second aberrations are spaced apart by the determined distance, and the second and third aberrations are spaced apart by the determined distance. 
     
     
         15 . The heater of  claim 14  wherein the first, second and third aberrations are spaced apart to form a line. 
     
     
         16 . The heater of  claim 11  wherein the liquid is an e-liquid comprising at least one of vegetable glycerine, propylene glycol, nicotine and a flavoring. 
     
     
         17 . The heater of  claim 11  wherein the liquid is an e-liquid comprising a cannabinoid. 
     
     
         18 . The heater of  claim 11  wherein the heating objective is to constrain production of droplets over a threshold diameter to below a defined quantity. 
     
     
         19 . The heater of  claim 18  wherein the threshold diameter is 10 microns. 
     
     
         20 . A pod for storing an atomizable e-liquid having a set of physical characteristics, the pod for use in a vaping device, having an airflow passage therethrough, the pod comprising:
 a reservoir for storing the atomizable e-liquid;   a wick, in fluid communication with the reservoir for drawing the atomizable e-liquid across the length of the wick through capillary action; and   a heater in contact with the wick, and aligned with the airflow passage, the heater further comprising:
 a heating surface for transferring heat into the atomizable e-liquid to atomize the e-liquid drawn across the wick; and 
 first and second aberrations on the heating surface spaced apart by a distance determined in accordance with at least one of the set of physical characteristics and a heating objective.