Method and apparatus for high mass concentration nano particle generation

Patent metadata

Field	Value
Publication number	US-9845242-B2
Application number	US-28105707-A
Country	US
Kind code	B2
Filing date	Mar 2, 2007
Priority date	Mar 3, 2006
Publication date	Dec 19, 2017
Grant date	Dec 19, 2017

Abstract

A method and apparatus for generating nano particles, including but not limited to nano particles of Ceo, at high concentration. The invention uses a solid aerosol disperser in communication with a furnace tube having a vaporization chamber and a dilution chamber. A heating element surrounds the furnace tube. Heat from the heating element heats bulk materials contained within a gas flow in the vaporization chamber to a temperature sufficient to convert the bulk materials to a vapor phase. Vaporized bulk materials are then moved to a dilution chamber, where an inert gas is introduced through a dilution gas port. The flow of the inert gas into the dilution chamber through the dilution gas port is sufficient to eject the bulk material from the exit of the dilution chamber, thereby condensing the bulk material into nano sized particles in a gas flow of sufficient volume to prevent agglomeration of the nano sized particles.

First claim

The invention claimed is:

1. An apparatus for generating nano particles at high concentration comprising:
a. a solid aerosol disperser,
b. the solid aerosol disperser in communication with a furnace tube having a vaporization chamber, the vaporization chamber having an input end and an output end,
c. a heating element in proximity to said furnace tube, the heating element capable of heating bulk materials contained within a gas flow in the vaporization chamber to a temperature sufficient to convert the bulk materials to a vapor phase,
d. a dilution chamber having a cup receiver and an output end, the output end of the vaporization chamber in communication with the input end of the dilution chamber,
e. wherein the cup receiver has a cup receiver outlet at the outlet end and wherein the dilution chamber further comprises a dilution gas port disposed at the outlet end of the dilution chamber that is separate from the outlet of the cup receiver.

2. The apparatus of claim 1 further comprising an extraction port positioned between the solid aerosol disperser and the vaporization chamber where a portion of the gas flow may be extracted prior to introduction into the vaporization chamber.

3. The apparatus of claim 2 wherein the extraction port includes a separator where a portion of the bulk material having relatively larger particle sizes is separated and extracted prior to introduction into the vaporization chamber.

4. The apparatus of claim 3 wherein the separator is a cyclone, an impact device, or combinations thereof.

5. A method for generating nano particles at high concentration comprising the steps of:
a. generating flow of bulk particles in a first inert gas in a solid aerosol disperser,
b. introducing flow of bulk particles in the inert gas from the solid aerosol disperser into a vaporization chamber,
c. maintaining the vaporization chamber at a temperature sufficient to vaporize the bulk particles,
d. introducing the vaporized particles to a dilution chamber having a cup receiver and an exit, the exit maintained at a temperature sufficient to condense the bulk materials,
e. introducing a flow of a second inert gas into the dilution chamber through a dilution port, the second inert gas cooling the vaporized materials in the cup receiver, and the flow of the inert gas sufficient to eject the bulk material from the exit, thereby condensing the bulk material into nano sized particles in a gas flow of sufficient volume to prevent agglomeration of the nano sized particles.

6. The method of claim 5 wherein the bulk material is processed by milling the bulk material prior to introducing it to the solid aerosol disperser.

7. The method of claim 5 wherein the bulk material is selected from the group cerium oxide, carbon nano tubes, titanium dioxide, C 70 , C 76 , and C 84 .

8. The method of claim 5 wherein the bulk material is C 60 .

9. The method of claim 8 wherein the C 60 has a particle size of between about 1 μm and about 1.5 μm mass median aerodynamic diameter (MMAD) when it is introduced into the vaporization chamber.

10. The method of claim 8 wherein the C 60 has a particle size of between about 1 μm and about 5 μm mass median aerodynamic diameter (MMAD) when it is introduced into the solid aerosol disperser.

11. The method of claim 8 wherein the C 60 has a particle size of less than 100 nm count median diameter (CMD) when it is condensed as nano sized particles.

12. The method of claim 5 wherein the temperature sufficient to vaporize the bulk particles is between about 500° C. and 600° C.

13. The method of claim 5 wherein the gas flow rate into the vaporization chamber and the gas flow rate into the dilution chamber are adjusted to insure that the residence time that the vaporized bulk material is in the dilution chamber is no more than 30 seconds.

14. The method of claim 5 wherein the first and the second inert gas are selected from the group He, N 2 , Ar, Kr, Ne, and combinations thereof.

15. The method of claim 5 wherein a portion of the gas flow from the solid aerosol disperser is extracted prior to introduction into the vaporization chamber.

16. The method of claim 5 wherein the gas flow from the solid aerosol disperser is directed into a separator where a portion of the gas flow is extracted prior to introduction into the vaporization chamber.

17. The method of claim 16 wherein the separator is a cyclone, an impact regime, or combinations thereof.

18. The method of claim 5 wherein dilution materials are moved through the cup receiver essentially along a linear pathway.

Assignees

• Gupta Amit
• Forsythe William C
• Clark Mark L
• Battelle Memorial Institute

Inventors

• Gupta Amit
• Forsythe William C
• Clark Mark L

Classifications

• B82Y30/00 Primary

  Nanotechnology for materials or surface science, e.g. nanocomposites · CPC title

• C01P2002/72

  by d-values or two theta-values, e.g. as X-ray diagram · CPC title

• C01P2004/64

  Nanometer sized, i.e. from 1-100 nanometer · CPC title

• C01P2002/82

  by IR- or Raman-data · CPC title

• B82Y40/00

  Manufacture or treatment of nanostructures · CPC title