Device and method for magnetic field-assisted simulation of zero-microgravity fame synthesis of nanoparticles

Patent metadata

Field	Value
Publication number	US-11786882-B2
Application number	US-202218245331-A
Country	US
Kind code	B2
Filing date	Apr 27, 2022
Priority date	May 8, 2021
Publication date	Oct 17, 2023
Grant date	Oct 17, 2023

Abstract

A device for magnetic field-assisted simulation of zero-microgravity flame synthesis of nanoparticles includes a gradient magnetic field device, a combustor and a product collection device. The gradient magnetic field device is composed of two magnetic field devices arranged face to face. The combustor is located between the two magnetic field devices. The outlet of the combustor is vertically upward. The position is below the magnetic field center of the gradient magnetic field device. The body force acting on the flame and surrounding magnetic species thereof by the gradient magnetic field device counteracts the gravitational buoyancy lift effect, so that flame synthesis is carried out under a simulated zero/microgravity flame to prepare the nanoparticles. The device is able to use a gradient magnetic field to simulate the zero/microgravity flame on the ground to synthesize the nanoparticles under special flame characteristics, with reduced flame disturbance, improved stability, and no overheated region.

First claim

What is claimed is:

1. A device for magnetic field-assisted simulation of zero-microgravity flame synthesis of nanoparticles, wherein the method comprises a gradient magnetic field device, a combustor and a product collection device; the gradient magnetic field device is composed of two magnetic field devices arranged face to face, the combustor is located between the two magnetic field devices, the outlet of the combustor is vertically upward, and the position is below the magnetic field center of the gradient magnetic field device; when the use environment is the ground, and the purpose is to simulate a microgravity flame, the direction of the outlet of the combustor is vertically upward, opposite to the direction of a gradient magnetic field generated by the gradient magnetic field device, and at this time, oxygen is subjected to a vertically upward magnetic field gradient force, making the gradient magnetic field force counteract gravity, and the product collection device is located downstream of the flame to collect a synthesized target product; when the use environment is a microgravity environment, and the purpose is to simulate a constant gravity flame, the direction of the outlet of the combustor is the same as a magnetic field gradient direction, at this time, oxygen is subjected to a magnetic field gradient force in the same direction as the outlet of the combustor, making the magnetic field gradient force equivalent to gravity, and constant gravity flame synthesis is simulated in the microgravity environment.

2. The device for magnetic field-assisted simulation of zero-microgravity flame synthesis of nanoparticles according to claim 1 , wherein the gradient magnetic field device is an electromagnet or a permanent magnet or a Helmholtz coil capable of providing a gradient magnetic field of a required intensity, the gradient magnitude

B
·

dB
dz

is 20-40 T 2 /m, wherein

B
·

dB
dz

is the magnetic field gradient of the gradient magnetic field in the vertical z direction, T is the unit of a magnetic field intensity, Tesla, and m is the unit of a length, meter.

3. The device for magnetic field-assisted simulation of zero-microgravity flame synthesis of nanoparticles according to claim 1 , wherein the combustor comprises a coaxial combustor, a McKenna flat flame premixed combustor, a Hencken combustor, or an atomizing nozzle combustor.

4. The device for magnetic field-assisted simulation of zero-microgravity flame synthesis of nanoparticles according to claim 3 , wherein a precursor steam is at the center inside the coaxial combustor, a fuel is on the periphery of the precursor steam, an oxidant is on the periphery of the fuel, and the oxidant, the fuel and the precursor steam synthesize a flame at the outlet of the combustor.

5. The device for magnetic field-assisted simulation of zero-microgravity flame synthesis of nanoparticles according to claim 1 , wherein the product collection device comprises a fibrous filter or a thermophoretic collection device to collect nanoparticle products downstream of the flame.

6. The device for magnetic field-assisted simulation of zero-microgravity flame synthesis of nanoparticles according to claim 1 , wherein the synthesized target product comprises metal oxides, non-metal oxides, carbon nanoparticles or nanofilms.

7. A method for magnetic field-assisted simulation of zero-microgravity flame synthesis of nanoparticles of the device according to claim 1 , wherein a coaxial combustor, a McKenna flat flame premixed combustor, a Hencken combustor or an atomizing nozzle combustor is used, a precursor steam of target nanoparticles, a fuel and an oxidant are introduced into the combustor, the fuel is ignited at the outlet of the combustor and the flow rate of gas in each path is adjusted to obtain a suitable flame, the flame is placed in the gradient magnetic field device, the magnitude of a magnetic field gradient is adjusted to enable the flame to form a zero-microgravity flame, and zero-microgravity flame synthesis of nanoparticles is simulated by passing through a product collection device to become target product-nanoparticles.

8. The method for magnetic field-assisted simulation of zero-microgravity flame synthesis of nanoparticles according to claim 7 , wherein air at the outlet of the combustor is a paramagnetic substance, and under the effect of a magnetic field with the gradient direction vertically upward, the air will be subjected to a vertically upward magnetic body force effect; in the vertical z direction, the magnetization force borne by air per unit volume is expressed as:

F
m

=

χ

μ
0

⁢

B
·

dB
dz

(
1
)

in the above formula, F m is the magnetization force borne by the air per unit volume, μ 0 is the vacuum permeability, χ is the volume susceptibility of the air, and

B
·

dB
dz

is the magnetic field gradient of the gradient magnetic field in the vertical z direction.

9. The method for magnetic field-assisted simulation of zero-microgravity flame synthesis of nanoparticles according to claim 8 , wherein gas in the flame under constant gravity at the outlet of the combustor is heated, decreasing the density, and then rises, and this effect is a gravitational buoyancy lift effect; the magnetic field gradient generated by the gradient magnetic field is used for having a vertically upward magnetic buoyancy lift effect on the air around the flame, which is equivalent to having a vertically downward buoyancy lift effect on the gas inside the flame; and when the magnetic buoyancy lift effect of the gradient magnetic field on the inside of the flame and the gravitational buoyancy lift effect counteract with each other, a zero-microgravity flame is formed.

10. Application of the device for magnetic field-assisted simulation of zero-microgravity flame synthesis of nanoparticles according to claim 1 , wherein the device for magnetic field-assisted simulation of zero-microgravity flame synthesis of nanoparticles is used for an orbit satellite and a lunar surface in a microgravity environment.

Assignees

• Univ Southeast

Inventors

• Duan Lunbo
• Gao Hetong
• Sun Zhenkun
• Li Tianxin

Classifications

• B01J19/087 Primary

  employing electric or magnetic energy · CPC title

• B01J19/0033

  Optimalisation processes, i.e. processes with adaptive control systems (adaptive control systems per se G05B13/00) · CPC title

• B82Y40/00 Primary

  Manufacture or treatment of nanostructures · CPC title

• B01J2219/00495

  Means for heating or cooling the reaction vessels · CPC title

• B01J2219/085

  creating magnetic fields · CPC title