Apparatus and methods for particle separation by ferrofluid constriction

Patent metadata

Field	Value
Publication number	US-2018369832-A1
Application number	US-201715634231-A
Country	US
Kind code	A1
Filing date	Jun 27, 2017
Priority date	Jun 27, 2017
Publication date	Dec 27, 2018
Grant date	—

Abstract

Methods for separating particles in a ferrofluid, along with apparatus for performing the same, are provided. The method may include introducing the ferrofluid through a separation tube; applying a magnetic field to the separation tube such that a fluid constriction is created within the tube that leads to a density gradient in the fluid with a maximum value (dmax) at some region along the tube; and introducing a plurality of particles into the ferrofluid within the separation tube such that particles having densities greater than dmax flow through the ferrofluid.

First claim

What is claimed is:

1 . A method of separating particles in a ferrofluid, the method comprising:
introducing the ferrofluid through a separation tube; applying a magnetic field to the separation tube such that a fluid constriction is created within the tube that leads to a density gradient in the fluid with a maximum value (d max ) at some region along the tube; and introducing a plurality of particles into the ferrofluid within the separation tube, wherein particles having densities greater than d max flow through the ferrofluid.

2 . The method of claim 1 , wherein particles having densities less than d max remain in the ferrofluid.

3 . The method of claim 1 , wherein the separation tube is oriented with a vertical vector such that gravity pulls the particles having densities greater than d max through the ferrofluid and past the region of d max .

4 . The method of claim 3 , wherein the separation tube is oriented substantially vertically such that gravity pulls the particles having densities greater than d max through the ferrofluid to the bottom of the separation tube.

5 . The method of claim 1 , further comprising:
opening a first valve attached to the separation tube to allow the particles having densities greater than d max flow from the separation tube through the first valve into a holding tube.

6 . The method of claim 5 , further comprising:
closing the first valve; and opening a second valve to collect the particles having densities greater than d max from the holding tube.

7 . The method of claim 5 , further comprising:
closing the first valve; and opening an inverted Y valve to allow the particles having densities greater than d max flow through the inverted Y valve into a first collection tube.

8 . The method of claim 7 , further comprising:
closing the inverted Y valve to the first collection tube; removing the magnetic field from the separation tube so that particles having densities less than d max flow through the ferrofluid.

9 . The method of claim 8 , further comprising:
opening the first valve to allow particles having densities less than d max flow through into the holding tube; and opening the inverted Y valve to allow the particles having densities less than d max flow through the inverted Y valve into a second collection tube.

10 . The method of claim 1 , wherein the particles are nonmagnetic.

11 . A particle separation device, comprising:
a separation tube defining an inlet at a first end and an outlet at a second end; a magnet positioned adjacent to or straddling the separation tube; a first valve positioned at the second end; a holding tube having a first end in communication with the separation tube via the first valve; and a second valve in communication with a second end of the holding tube.

12 . The particle separation device of claim 11 , wherein the separation tube is oriented with a vertical vector.

13 . The particle separation device of claim 11 , wherein the separation tube is oriented substantially vertically.

14 . The particle separation device of claim 11 , wherein the second valve is an inverted Y valve in independent communication with a first collection tube and a second collection tube.

15 . The particle separation device of claim 11 , wherein the separation tube is constructed of a non-magnetic material.

Assignees

• Gen Electric

Inventors

• Roth Paul Gregory

Classifications

• B22F1/14

  Treatment of metallic powder (mixing with lubricating or binding agents or with organic material B22F1/10) · CPC title

• B03C2201/20

  Magnetic separation of bulk or dry particles in mixtures · CPC title

• B03C1/32 Primary

  acting on the medium containing the substance being separated, e.g. magneto-gravimetric-, magnetohydrostatic-, or magnetohydrodynamic separation · CPC title

• B22F1/0081

  Operations & Transport · mapped topic

• B22F2202/05

  Use of magnetic field · CPC title