Devices and methods for removing nano-particulates from gases

Patent metadata

Field	Value
Publication number	US-9744495-B2
Application number	US-201214427037-A
Country	US
Kind code	B2
Filing date	Sep 10, 2012
Priority date	Sep 10, 2012
Publication date	Aug 29, 2017
Grant date	Aug 29, 2017

Abstract

Systems and methods are disclosed for removing nano-particulates from a gas. The systems may include a chamber to contain the particulate-containing gas, a source of the gas, a source of water vapor, a source of a supersonic gas, and at least one ultrasonic transducer in contact with the chamber. The chamber may also include one or more receptacles to receive the particulates. The methods may include introducing the particulate-containing gas and the water vapor into the chamber. A gas may be introduced into the chamber at supersonic speeds thereby cooling the water vapor to form nucleating ice crystals. The ultrasonic transducers may then introduce ultrasonic power into the chamber thereby causing the particulates to contact the ice crystals. The nucleating crystals, with their attached particulates, may then fall under gravity to be captured in the receptacles.

First claim

What is claimed is:

1. A system to remove a plurality of particulates from a particulate-containing gas, the system comprising:
a chamber;
a source of the particulate-containing gas, comprising an inlet valve in fluid communication with the chamber;
a source of a supersonic gas in fluid communication with the chamber, wherein the supersonic gas is a non-flammable gas;
a source of water vapor in fluid communication with the chamber; and
at least one ultrasonic transducer in acoustic communication with the chamber.

2. The system of claim 1 , wherein the chamber has a rectangular cross section or a circular cross section.

3. The system of claim 1 , wherein the source of the supersonic gas comprises a gas accelerating inlet comprising a first side and a second side, and a source of a cooling gas, wherein the first side of the gas accelerating inlet is in fluid communication with the source of the cooling gas and the second side of the gas accelerating inlet is in fluid communication with the chamber.

4. The system of claim 3 , wherein the gas accelerating inlet is a de Laval nozzle.

5. The system of claim 3 , wherein the cooling gas is a dry non-flammable gas.

6. The system of claim 3 , wherein the cooling gas is one or more of the following: dry air, dry argon, and dry carbon dioxide.

7. The system of claim 3 , further comprising:
a gas compressor in fluid communication with the source of the cooling gas;
a pressure meter in fluid communication with the first side of the gas accelerating inlet;
a valve disposed between the source of the cooling gas and the first side of the gas accelerating inlet; and
a control system configured to control at least one activity of the valve.

8. The system of claim 1 , wherein the source of water vapor comprises a water inlet valve with a first side and a second side, wherein the first side of the water inlet valve is in fluid communication with an ultrasonic atomizer, and the second side of the water inlet valve is in fluid communication with the chamber.

9. The system of claim 8 , wherein the ultrasonic atomizer comprises at least one piezo-electric element.

10. The system of claim 9 , wherein the at least one piezo-electric element is configured to operate at a frequency about 0.1 MHz to about 1 MHz.

11. The system of claim 8 , further comprising a controller of the ultrasonic atomizer.

12. The system of claim 1 , wherein the chamber comprises at least two opposing walls, and the at least one ultrasonic transducer is in acoustic communication with each of the at least two opposing walls.

13. The system of claim 1 , wherein the at least one ultrasonic transducer is configured to operate at about 1 MHz to about 100 MHz.

14. The system of claim 1 , wherein the at least one ultrasonic transducer is configured to produce less than or about 750 W of power.

15. The system of claim 1 , wherein the at least one ultrasonic transducer is a piezoelectric transducer.

16. The system of claim 1 , wherein the at least one ultrasonic transducer is placed in acoustic communication with at least one exterior surface of the chamber.

17. The system of claim 1 , wherein the chamber has at least one dimension, the at least one dimension sized to promote an acoustic resonance at a wavelength produced by the at least one ultrasonic transducer.

18. The system of claim 1 , further comprising at least one receptacle disposed within the chamber and configured to receive at least a portion of the plurality of particulates.

19. A method to remove particulates from a gas, the method comprising:
introducing a first gas comprising a non-flammable gas and a plurality of particulates into a chamber;
introducing atomized water into the chamber;
introducing ultrasonic power into the chamber;
introducing a supersonic second gas into the chamber to cool at least some of the atomized water to form a plurality of nucleating ice crystals;
allowing a plurality of water droplets to form on at least some of the plurality of nucleating ice crystals;
allowing the ultrasonic power to induce at least some of the plurality of particulates to contact the water droplets; and
collecting the plurality of water droplets and the plurality of particulates in contact therewith.

20. The method of claim 19 , wherein introducing the first gas comprises introducing a first dry non-flammable gas.

21. The method of claim 19 , wherein introducing the first gas comprising the non-flammable gas and the plurality of particulates comprises introducing a first dry non-flammable gas comprising the plurality of particulates having an average size of about 10 nm to about 1 μm.

22. The method of claim 19 , wherein introducing the first gas into the chamber comprises pumping the first gas into the chamber.

23. The method of claim 19 , wherein introducing the atomized water into the chamber comprises introducing about 1 L to about 20 L of the atomized water.

24. The method of claim 19 , wherein introducing the ultrasonic power into the chamber comprises introducing the ultrasonic power into the chamber in a continuous manner or in a pulsed manner.

25. The method of claim 19 , wherein introducing the ultrasonic power into the chamber comprises introducing the ultrasonic power into the chamber in a pulsed manner having a duty cycle of about 50% to about 100%.

26. The method of claim 19 , wherein introducing the supersonic second gas into the chamber comprises introducing the supersonic second gas is introduced into the chamber at a speed of about Mach 1 to about Mach 2.

Assignees

• Tu Juan
• Lin Han
• Liang Bin
• Nanjing University Of Technology

Inventors

• Tu Juan
• Lin Han
• Liang Bin

Classifications

• B01D47/066 Primary

  with nozzles using mechanical vibrations · CPC title

• B01D47/06 Primary

  Spray cleaning · CPC title

• B01D49/006

  by sonic or ultrasonic techniques · CPC title

• B01D5/0033

  Other features · CPC title