Separation of multi-component fluid through ultrasonic acoustophoresis

Patent metadata

Field	Value
Publication number	US-9340435-B2
Application number	US-201514711627-A
Country	US
Kind code	B2
Filing date	May 13, 2015
Priority date	Mar 15, 2012
Publication date	May 17, 2016
Grant date	May 17, 2016

Abstract

An acoustic standing wave is utilized to separate components from a multi-component fluid, such as oil from an oil-water mixture, in a fluid flow scheme with an acoustophoresis device. For example, the flow scheme and device allows for trapping of the oil as the oil coalesces, agglomerates, and becomes more buoyant than the water.

First claim

The invention claimed is:

1. A method for increasing the particle size of a secondary fluid in an emulsion or mixture of a host fluid and the secondary fluid, comprising:
flowing the emulsion or mixture through an acoustophoresis device that comprises:
a flow chamber having an inlet and an outlet; and
at least one piezoelectric transducer and reflector pair positioned on opposing sides of the flow chamber; and

driving the piezoelectric transducer of the at least one piezoelectric transducer and reflector pair to form a three-dimensional acoustic standing wave in the flow chamber, such that incoming smaller droplets of the secondary fluid are trapped in the three-dimensional acoustic standing wave, resulting in coalescence or agglomeration of the smaller droplets into larger droplets,
wherein the drag or buoyancy of the larger droplets causes them to be removed from the three-dimensional acoustic standing wave and to follow the flow of the host fluid.

2. The method of claim 1 , where the secondary fluid is immiscible with the host fluid.

3. The method of claim 1 , where the dispersed droplets are an emulsified fluid.

4. The method of claim 1 , where the incoming smaller droplets of the secondary fluid are less than 5 microns in size.

5. The method of claim 1 , wherein the emulsion or mixture flows through the acoustophoresis device at a flow rate of about 250 ml/min to about 1000 ml/min.

6. The method of claim 1 , wherein the piezoelectric transducer of the at least one piezoelectric transducer and reflector pair is operated at a frequency of about 3 MHz.

7. The method of claim 1 , wherein the particle size of the secondary fluid exiting the flow chamber is increased by at least 50 microns.

8. The method of claim 1 , wherein the volume of the secondary fluid present in droplets having a particle size of 20 microns or less is less than 20% of the total volume of the secondary fluid.

9. The method of claim 1 , wherein the flow chamber has a plurality of piezoelectric transducer and reflector pairs.

10. The method of claim 1 , wherein the piezoelectric transducer of the at least one piezoelectric transducer and reflector pair comprises:
a housing having a top end, a bottom end, and an interior volume; and
a piezoelectric crystal at the bottom end of the housing having an exposed exterior surface and an interior surface, the crystal being able to vibrate when driven by a voltage signal.

11. The method of claim 10 , wherein no backing layer is present within the housing of the transducer, and an air gap is present in the interior volume between the crystal and a top plate at the top end of the housing.

12. The method of claim 10 , wherein the transducer further comprises a backing layer contacting the interior surface of the crystal, the backing layer being made of a substantially acoustically transparent material.

13. The method of claim 1 , wherein the three-dimensional acoustic standing wave results in an acoustic radiation force having an axial component and a lateral component that are of the same order of magnitude.

14. A device for increasing the particle size of a secondary fluid in an emulsion or mixture of a host fluid and the secondary fluid, comprising:
a flow chamber having an inlet and an outlet; and
at least one piezoelectric transducer and reflector pair positioned on opposing sides of the flow chamber such that a three-dimensional acoustic standing wave is formed within the flow chamber between the piezoelectric transducer and the reflector of the at least one piezoelectric transducer and reflector pair;
whereby incoming smaller droplets of the secondary fluid dispersed in the host fluid are trapped by the three-dimensional acoustic standing waves, are coalesced or agglomerated into larger droplets in the three-dimensional acoustic standing waves, and wherein the drag or buoyancy of the larger droplets causes the larger droplets to be removed from the three-dimensional acoustic standing wave and to follow the flow of the host fluid.

15. The device of claim 14 , where multiple piezoelectric transducer and reflector pairs are adjacent to each other.

16. The device of claim 14 , where the reflector is a piezoelectric transducer.

17. The device of claim 14 , wherein the three-dimensional acoustic standing wave results in an acoustic radiation force having an axial component and a lateral component that are of the same order of magnitude.

18. A method for increasing the particle size of a secondary fluid in an emulsion or mixture of a host fluid and the secondary fluid, comprising:
flowing the emulsion or mixture through an acoustophoresis device that comprises:
a flow chamber having an inlet and an outlet; and
at least one piezoelectric transducer and reflector pair positioned on opposing sides of the flow chamber; and

driving the piezoelectric transducer of the at least one piezoelectric transducer and reflector pair to form a multi-dimensional acoustic standing wave in the flow chamber, such that incoming smaller droplets of the secondary fluid are trapped in the multi-dimensional acoustic standing wave, resulting in coalescence or agglomeration of the smaller droplets into larger droplets,
wherein the drag or buoyancy of the larger droplets causes the larger droplets to be removed continuously from the multi-dimensional acoustic standing wave and to follow the flow of the host fluid.

Assignees

• Flodesign Sonics Inc
• Flodesign Sonics Inc

Inventors

• Lipkens Bart
• Dionne Jason
• Mercado Ari
• Dutra Brian
• Presz Jr Walter M
• Kennedy Iii Thomas J
• Masi Louis

Classifications

• B01D43/00 Primary

  Separating particles from liquids, or liquids from solids, otherwise than by sedimentation or filtration (flotation processes B03D1/00; drying solid materials or objects F26B) · CPC title

• C02F2103/10

  from quarries or from mining activities · CPC title

• B01D17/12

  Auxiliary equipment particularly adapted for use with liquid-separating apparatus, e.g. control circuits · CPC title

• B06B1/0644

  using a single piezoelectric element (B06B1/0688 takes precedence) · CPC title

• B01D17/045

  with coalescers · CPC title