Vaporizer including positive temperature coefficient of resistivity heater
A vaporizer device includes a housing including an air inlet, a heating element within the housing and a heat exchanger. The heating element includes a nonlinear positive temperature coefficient of resistance material. The heat exchanger is thermally coupled to the heating element and arranged to receive airflow from the air inlet. The heat exchanger is configured to transfer heat between the heating element and the airflow to produce a heated airflow. The heated airflow exiting the heat exchanger is configured to vaporize a vaporizable material. Related apparatus, systems, techniques and articles are also described.
1. A vaporizer device comprising:
a housing including an air inlet;
a heating element within the housing, the heating element including a nonlinear positive temperature coefficient of resistance material including an electrical resistivity transition zone in which electrical resistivity increases over a temperature range, such that when the heating element is heated above a first temperature within the electrical resistivity transition zone, current flow from a power source is reduced to a level that limits further temperature increases of the heating element; and
a heat exchanger thermally coupled to the heating element and arranged to receive an airflow from the air inlet, the heat exchanger configured to transfer heat between the heating element and the airflow to produce a heated airflow, wherein the heated airflow exiting the heat exchanger is configured to vaporize a vaporizable material.
2. The vaporizer device of claim 1 , wherein the heat exchanger includes a first heat exchanger thermally coupled to a first side of the heating element, the heat exchanger including a second heat exchanger thermally coupled to a second side of the heating element.
3. The vaporizer device of claim 1 , wherein the heat exchanger includes a plurality of fin features.
4. The vaporizer device of claim 1 , wherein the heat exchanger is made from aluminum, copper, steel, stainless steel, or titanium.
5. The vaporizer device of claim 1 , wherein the heat exchanger is made from a thermally conductive material extrusion or a metal foam.
6. The vaporizer device of claim 1 , further comprising:
a flow diverter located in a path of the airflow and configured to divert a portion of the airflow through the heat exchanger.
7. The vaporizer device of claim 1 , further comprising:
a product cover containing the vaporizable material.
8. The vaporizer device of claim 7 , wherein the product cover includes a cartridge disposed therein.
9. The vaporizer device of claim 8 , wherein the cartridge includes a reservoir, a liquid vaporizable material within the reservoir, and a wick in fluidic communication with the liquid vaporizable material, wherein the cartridge is configured to receive the heated airflow through a first air inlet and direct the heated airflow over the wick.
10. The vaporizer device of claim 9 , wherein the cartridge includes a mouthpiece, and the wick is located in a path of the heated airflow between the heating element and the mouthpiece.
11. The vaporizer device of claim 9 , wherein the cartridge includes a second air inlet configured to draw a second airflow into the cartridge for mixing with the heated airflow.
12. The vaporizer device of claim 11 , wherein the second air inlet is located within a mouthpiece of the cartridge.
13. The vaporizer device of claim 8 , wherein the cartridge is a first cartridge, and the vaporizer device further comprises a second cartridge.
14. The vaporizer device of claim 13 , wherein the second cartridge includes a second air inlet for mixing ambient temperature air with an aerosol.
15. The vaporizer device of claim 13 , further comprising:
a fibrous body arranged to receive and cool the aerosol after the vapor and/or the first aerosol passes through the vaporizable material.
16. The vaporizer device of claim 1 , wherein the electrical resistivity transition zone begins at the first temperature of between 150° C. and 350° C.
17. The vaporizer device of claim 16 , wherein the electrical resistivity transition zone begins at the first temperature of between 220° C. and 300° C.
18. The vaporizer device of claim 17 , wherein the electrical resistivity transition zone begins at the first temperature between 240° C. and 280° C.
19. The vaporizer device of claim 1 , wherein the increase in the electrical resistivity over the temperature range of the electrical resistivity transition zone includes an increase factor of at least 10, the increase factor characterizing a relative change in electrical resistivity between electrical resistivity at the first temperature associated with a start of the electrical resistivity transition zone and electrical resistivity at a second temperature associated with an end of the electrical resistivity transition zone.
20. The vaporizer device of claim 1 , wherein the electrical resistivity transition zone begins at the first temperature and the electrical resistivity of the heating element at temperatures below the first temperature is between 0.2 ohm-cm and 200 ohm-cm.