Acoustophoretic enhanced system for use in tanks

Patent metadata

Field	Value
Publication number	US-9718708-B2
Application number	US-201313866943-A
Country	US
Kind code	B2
Filing date	Apr 19, 2013
Priority date	Apr 20, 2012
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

A system for enhancing the separation of particles or fluids from water is disclosed. A settling tank or skim tank is provided with an open submersible acoustophoretic separator. In a skim tank, the separator captures and holds oil droplets or particles, permitting them to coalesce until they are large enough and have sufficient buoyant force to float to the top of the tank. In a settling or sediment tank, separator captures and holds particles until they are large enough that the force of gravity causes them to settle out of the water. The acoustophoretic device thus speeds up separation of the particles or droplets from the water.

First claim

The invention claimed is:

1. A method of accelerating separation in a tank or vessel, the method comprising:
placing a submersible acoustophoretic separator in the tank or vessel, the acoustophoretic separator having (i) a housing having (a) a transducer on a transducer face, (b) a reflector on a reflector face opposite the transducer face, (c) a support joining the transducer face and the reflector face, and (d) at least one exposed face that allows fluid to enter a separation area located between the transducer face and the reflector face;
providing a fluid in the tank or vessel, the fluid having a first density and containing particles or droplets having a different density;
applying acoustic energy to the fluid with the transducer to create a multimode acoustic standing wave between the transducer and the reflector, wherein the fluid is separated from the particles or droplets by the multimode acoustic standing wave, and wherein the multimode acoustic standing wave results in an acoustic radiation force having an axial force component and a lateral force component that are of the same order of magnitude.

2. The method of claim 1 , wherein the standing wave creates nodal lines and lateral forces that trap the particles or droplets in the nodal lines.

3. The method of claim 2 , wherein the particles or droplets trapped in the nodal lines coalesce or agglomerate such that the particles or droplets are separated from the fluid.

4. The method of claim 3 , wherein the at least one exposed face of the submersible acoustophoretic separator is a top face, allowing the trapped particles or droplets to exit the separator as they coalesce or agglomerate.

5. The method of claim 1 , wherein the fluid is circulated in the tank or vessel to move fluid through the separator.

6. The method of claim 1 , wherein the fluid is flowed between the transducer and the reflector.

7. The method of claim 1 , wherein the transducer includes a ceramic crystal made of PZT-8.

8. The method of claim 1 , wherein the housing is adjustable to vary the distance between the transducer and the reflector.

9. The method of claim 1 , wherein the support includes an upper support plate connecting an upper edge of the transducer face to an upper edge of the reflector face and support rods connecting a lower edge of the transducer face to a lower edge of the reflector face.

10. The method of claim 9 , wherein the housing includes wheels or treads for propelling the separator on the bottom of the tank or vessel.

11. The method of claim 9 , wherein the housing includes a flotation device.

12. The method of claim 9 , wherein the separator is suspended from a boom that rotates about a central support.

13. The method of claim 1 , wherein the support is a set of support rods connecting a lower edge of the transducer face to a lower edge of the reflector face.

14. The method of claim 1 , wherein the support is an upper support structure connecting an upper edge of the transducer face to an upper edge of the reflector face.

15. The method of claim 1 , wherein the housing includes wheels or treads for propelling the separator on the bottom of the tank or vessel.

16. The method of claim 1 , wherein the submersible acoustophoretic separator further comprises a flotation device.

17. The method of claim 13 , wherein each of the support rods is a telescoping support rod.

18. The method of claim 1 , wherein the transducer creates a three-dimensional acoustic standing wave.

19. The method of claim 1 , wherein the submersible acoustophoretic separator includes a total of three exposed faces.

20. The method of claim 3 , wherein the at least one exposed face of the submersible acoustophoretic separator is a bottom face, allowing the agglomerated particles or droplets in the standing waves to exit the separator once they are of sufficient size to sink to a bottom of the tank or vessel.

21. A method of separation in a tank or vessel, comprising:
placing a submersible acoustophoretic separator in the tank or vessel, the acoustophoretic separator having (i) a housing having (a) at least one transducer and (b) at least one reflector;
wherein the tank or vessel contains a host fluid and at least one secondary phase;
wherein the transducer is composed of a piezoelectric material and the reflector is made of a high acoustic impedance material;
applying acoustic energy to the fluid with the transducer to create a multimode acoustic wave;
reflecting the multimode acoustic wave from the reflector, thereby creating a multimode acoustic standing wave, wherein the multimode acoustic standing wave is exposed to the host fluid and the at least one secondary phase in the tank or vessel; and
separating the at least one secondary phase from the host fluid in an accelerated manner due to exposure to the multimode acoustic standing wave; and
wherein the multimode acoustic standing wave results in an acoustic radiation force having an axial force component and a lateral force component that are of the same order of magnitude.

22. The method of claim 21 , wherein the submersible acoustophoretic separator includes a total of three exposed faces that allow the host fluid and the at least one secondary phase to enter a separation area located between the transducer and the reflector.

23. The method of claim 21 , wherein the multimode acoustic standing wave is a three-dimensional acoustic standing wave.

24. A method of accelerating separation in a tank or vessel, comprising:
placing an acoustophoretic separator in the tank or vessel, the acoustophoretic separator having (i) a housing having (a) at least one transducer and (b) at least one reflector;
wherein the tank or vessel contains (i) a host fluid and (ii) (a) dispersed particles or (b) a secondary fluid;
wherein the transducer is composed of a piezoelectric material and the reflector is made of a high acoustic impedance material;
applying acoustic energy to the host fluid with the transducer to create a multimode acoustic wave;
reflecting the multimode acoustic wave from the reflector, thereby creating a multimode acoustic standing wave, wherein the multimode acoustic standing wave is exposed to the host fluid and the dispersed particles or secondary fluid in the tank or vessel; and
coalescing, agglomerating, or precipitating the dispersed particles or secondary fluid into larger particles or droplets so that the larger particles or droplets settle or float out of the host fluid in an accelerated manner due to exposure to the multimode acoustic standing wave;
wherein the multimode acoustic standing wave results in an acoustic radiation force having an axial force component and a lateral force component that are of the same order of magnitude.

25. The method of claim 24 , wherein the acoustic separator floats on the surface of the host fluid.

26. The method of claim 24 , wherein the acoustic separator is submerged in the host fluid.

27. The method of claim 24 , wherein the multimode acoustic standing wave is a three-dimensional acoustic standing wave.

Assignees

• Flodesign Sonics Inc

Inventors

• Loricco Nicholas M
• Lipkens Bart

Classifications

• B01D21/283 Primary

  Settling tanks provided with vibrators · CPC title

• C02F1/36 Primary

  ultrasonic vibrations · CPC title

• H04R23/00

  Transducers other than those covered by groups H04R9/00 - H04R21/00 {(diaphragms for transducers of the distributed-mode type H04R7/045)} · CPC title