Nozzle, device, and method for high-speed generation of uniform nanoparticles

• US 10,081,091 B2
• Filed: 11/02/2016
• Issued: 09/25/2018
• Est. Priority Date: 06/12/2015
• Status: Active Grant

• Current Assignee: Postech Academy-Industry Foundation
• Original Assignee: Postech Academy-Industry Foundation
• Inventors: Lee, Jin Won, Kim, In Ho
• Primary Examiner(s): Le, Viet
• Application Number:
  US15/341,288
• Publication Number:
  US 20170072537A1
• Time in Patent Office: 692 Days
• Field of Search: 239272, 239433, 239593
• CPC Class Codes: B24C 1/003 using material which dissolves or changes phase after the treatment, e.g. ice, CO2
• CPC Class Codes: B24C 5/04 Nozzles therefor nozzles in general B05B

Abstract

A nozzle, a device, and a method for high-speed generation of uniform nanoparticles allow a particle generation gas formed of carbon dioxide to pass through the nozzle, thereby forming uniform nanoparticles at high speed. An orifice that adjusts an opening and closing cross-sectional area of a throat of the nozzle is provided to cause uniform nuclei generation without an additional cooling device, a dilating portion that has a cross-sectional area and a dilation angle increasing toward an outlet side of the nozzle is provided to grow the nuclei through a first dilation portion (having a relatively gradual dilation angle) and thus cause particle generation, and the generated particles are accelerated through a second dilating portion that has a steeper dilation angle than the first dilating portion.

Claims

1. A method of generating high-speed uniform nanoparticles by passing a particle generation gas formed of carbon dioxide through a nozzle, the method comprising:

generating nuclei by passing the particle generation gas through an orifice provided in a nozzle throat of the nozzle to expand the particle generation gas;

generating sublimation particles by passing the particle generation gas through a first dilating portion extended from an outlet of the nozzle throat and having a dilation angle of 0°

to 30°

to grow the nuclei; and

offsetting growth of a boundary layer and increasing speed of injecting the sublimation particles by passing the particle generation gas through a second dilating portion extended from an outlet of the first dilating portion and having an average dilation angle increased by 10°

to 45°

compared with the dilation angle of the first dilating portion.

2. The method according to claim 1, further comprising adjusting a pressure of the particle generation gas before the generating of nuclei.

3. The method according to claim 2, wherein the particle generation gas is adjusted to have a pressure of 5 bar to 60 bar and flows into the nozzle.

4. The method according to claim 1, further comprising:

before the generating of nuclei,

forming a mixture gas by mixing the particle generation gas and a carrier gas; and

adjusting a pressure of the mixture gas.

5. The method according to claim 4, wherein

the carrier gas is formed of nitrogen or helium, and

the mixture gas is adjusted to have a pressure of 5 bar to 120 bar and flows into the nozzle.

6. The method according to claim 1, further comprising, after the increasing of speed of injecting the sublimation particles, passing the particle generation gas through a third dilating portion extended from an outlet of the second dilating portion and having a dilation angle increased by 10°

to 45°

compared with the average dilation angle of the second dilating portion and lower than 90°

in maximum, and forming a high-speed core of the sublimation particles outside the nozzle, thereby controlling a flow of the particle generation gas.