Inductive heating assembly for inductive heating of an aerosol-forming substrate

Patent metadata

Field	Value
Publication number	US-12063970-B2
Application number	US-201917278739-A
Country	US
Kind code	B2
Filing date	Sep 24, 2019
Priority date	Sep 25, 2018
Publication date	Aug 20, 2024
Grant date	Aug 20, 2024

Abstract

An inductive heating assembly is configured to inductively heat an aerosol-forming substrate to a pre-determined operating temperature, the heating assembly including an induction source configured to generate an alternating electromagnetic field; and a susceptor assembly configured to inductively heat the aerosol-forming substrate under influence of the alternating magnetic field generated by the induction source, the susceptor assembly including a first susceptor including a first susceptor material and a second susceptor including a second susceptor material having a Curie temperature at least 50 degrees Celsius below an operating temperature of the heating assembly. An aerosol-generating device and an aerosol-generating system include the inductive heating assembly.

First claim

The invention claimed is:

1. An inductive heating assembly configured to inductively heat an aerosol-forming substrate to a pre-determined operating temperature, the heating assembly comprising:
an induction source configured to generate an alternating electromagnetic field; and
a susceptor assembly configured to inductively heat the aerosol-forming substrate under influence of the alternating magnetic field generated by the induction source, the susceptor assembly comprising a first susceptor comprising a first susceptor material and a second susceptor comprising a second susceptor material having a Curie temperature at least 50 degrees Celsius below an operating temperature of the heating assembly.

2. The heating assembly according to claim 1 , wherein the pre-determined operating temperature is at least 300 degrees Celsius.

3. The heating assembly according to claim 1 , wherein the pre-determined operating temperature is at least 400 degrees Celsius.

4. The heating assembly according to claim 1 , wherein the second susceptor material has a Curie temperature of at least 100 degrees Celsius below the operating temperature.

5. The heating assembly according to claim 1 , wherein the second susceptor material has a Curie temperature of at least 200 degrees Celsius below the operating temperature.

6. The heating assembly according to claim 1 , wherein the second susceptor material has a Curie temperature below 350 degrees Celsius.

7. The heating assembly according to claim 1 , wherein the second susceptor material has a Curie temperature below 200 degrees Celsius.

8. The heating assembly according to claim 1 , wherein the second susceptor comprises one of mu-metal or permalloy.

9. The heating assembly according to claim 1 , wherein the first susceptor material is electrically conductive and/or one of paramagnetic, ferromagnetic, or ferrimagnetic.

10. The heating assembly according to claim 1 , wherein the first susceptor material comprises one of aluminum, iron, nickel, copper, bronze, cobalt, plain-carbon steel, stainless steel, ferritic stainless steel, martensitic stainless steel, or austenitic stainless steel.

11. The heating assembly according to claim 1 ,
wherein the first susceptor material has a positive temperature coefficient of resistance, and
wherein the second susceptor material has a negative temperature coefficient of resistance.

12. The heating assembly according to claim 1 , wherein the first susceptor and the second susceptor are in intimate physical contact with each other.

13. The heating assembly according to claim 1 , wherein the first susceptor or the second susceptor or both the first and the second susceptor, or the entire susceptor assembly, is one of a particulate susceptor, or a susceptor filament, or a susceptor mesh, or a susceptor wick, or a susceptor pin, or a susceptor rod, or a susceptor blade, or a susceptor strip, or a susceptor sleeve, or a susceptor cup, or a cylindrical susceptor, or a planar susceptor.

14. The heating assembly according to claim 1 , further comprising a controller operatively connected to the induction source and configured to control operation of the induction source and to control heating of the aerosol-forming substrate to the pre-determined operating temperature.

15. The heating assembly according to claim 14 , wherein the controller is further configured to control operation of the induction source in a closed-loop configuration.

16. The heating assembly according to claim 14 , wherein the controller is further configured to determine, during preheating of the heating assembly starting at room temperature towards the pre-determined operating temperature, a minimum value of an apparent resistance occurring in a temperature range of ±5 degrees Celsius around a Curie temperature of the second susceptor material.

17. The heating assembly according to claim 1 , further comprising a DC power supply configured to provide a DC supply voltage and a DC supply current to the induction source.

18. An aerosol-generating device for generating an aerosol by heating an aerosol-forming substrate, the device comprising:
a receiving cavity configured to receive the aerosol-forming substrate to be heated; and
an inductive heating assembly according to claim 1 configured to inductively heat the aerosol-forming substrate within the receiving cavity.

19. An aerosol-generating system comprising an aerosol-generating device, an aerosol-generating article for the aerosol-generating device, and an inductive heating assembly according to claim 1 , wherein the induction source of the heating assembly is part of the aerosol-generating device, wherein the first susceptor of the susceptor assembly is part of the aerosol-generating article, and wherein the second susceptor of the susceptor assembly is part of the aerosol-generating article or part of the aerosol-generating device.

Assignees

• Philip Morris Products Sa

Inventors

• Zinovik Ihar Nikolaevich
• Taurino Irene

Classifications

• A24F40/51

  Arrangement of sensors · CPC title

• A24F40/53

  Monitoring, e.g. fault detection · CPC title

• A24F40/57

  Temperature control · CPC title

• A24F40/50

  Control or monitoring · CPC title

• A24F40/465 Primary

  specially adapted for induction heating · CPC title