US 4,900,414 A · Commercial separation system and method using electrokinetic techniques

Abstract

A commercial electrokinetic separation system extracts charged particles from fluids and separates the particles into discrete separation bands. An electrokinetic column of extended length has a plurality of alternatingly spaced layers of electrokinetic material and electrodes along its length. A traveling wave electrical field is established by applying an electrical potential between two adjacent or nearly adjacent electrodes at one end of the column and by moving the connections progressively to electrodes further along the column, working toward the other end. A fluid containing particles for separation is introduced in a chamber at said one end of the column where the traveling wave is initiated and particles having a phoretic speed equal or greater than the velocity of the traveling wave move from one end to the other end of the column, leaving behind all particles which have lesser phoretic speeds. The electrical source can be either AC or DC. Both negatively charged and positively charged particles may be separated from the fluid in separate sweeps of the traveling wave field when wave velocity corresponds to the particles's phoretic speed. Isoelectric and isotachophoresis focusing can be incorporated to separate different charged materials which have the same polarity of charge and the same phoretic speed.

Claims36

Dependent claims

A commercial electrokinetic separation system for separating charged particles of different types and charges one from the other, said charged particles being separated from an inputted fluid, comprising:

a plurality of layers of electrokinetic material;
a plurality of column electrodes, said column electrodes being spaced apart one from the other in a first direction, one said electrokinetic material layer being positioned between each pair of said column electrodes, each said column electrode being in electrical contact with said adjacent electrokinetic material layers and subject to connection to a power source, said column electrodes and associated layers forming an electrokinetic column, a first column electrode at one end of said column being exposed to said fluid, an electric field being created in said electrokinetic column causing one of attraction and repulsion between selected ones of said column electrodes and respective types of said charged particles when said selected column electrodes are connected to said power source;
a fluid chamber adjacent to said first column electrode at said one column end, said chamber being adapted to receive said fluid for contacting with said first column electrode;
and
a chamber electrode within said fluid chamber for contact with said fluid, said fluid being positioned between said chamber electrode and said first column electrode.

2 more elements

A method of separating charged particles from an inputted fluid using a commercial electrokinetic separation system including an electrokinetic column having a plurality of layers of electrokinetic material, a plurality of column electrodes, said column electrodes being spaced apart one from the other in a first direction, one said electrokinetic material layer being between each pair of said column electrodes, each said column electrode being in electrical contact with said adjacent electrokinetic material layers, a first electrode at one end of said column being exposed to said fluid, and a fluid chamber adjacent to said first electrode at said one column end, said chamber being adapted to receive said fluid for contacting with said first electrode, and a chamber electrode within said fluid chamber, said fluid being positioned between said chamber electrode and said first electrode of said column, comprising the steps:

(a) inputting said fluid into said chamber;
(b) connecting the D.C. voltage source between said chamber electrode and a column electrode creating an electrical field therebetween and drawing charged particles from said fluid into said column;
(c) maintaining said connections for a period of time;
(d) connecting the DC voltage source across a first pair of said column electrodes at said one end, an electrical field being created between said connected column electrodes, charged particles in said intervening electrokinetic material being attracted toward said connected electrodes;
(e) maintaining said connections for a period of time;
(f) unmaking the connections of step (d) as charged particles of interest approach the column electrode of said first pair farthest from said one end of said electrokinetic column;
(g) connecting a second pair of column electrodes to said DC source, said second pair of column electrodes straddling said particles of interest and creating a field having the same polarity as that created by said first pair of column electrodes, said particles of interest being attracted to the column electrode of said second pair farthest from said one end.

4 more elements

A method of separating charged particles from an inputted fluid using a commercial electrokinetic separation system including an electrokinetic column having a plurality of layers of electrokinetic material, a plurality of column electrodes and strip electrodes, said column electrodes being spaced apart one from the other in a first direction, said strip electrodes being spaced apart in a second transverse direction, one said electrokinetic material layer being between each pair of said column and strip electrodes, each said column and strip electrode being in electrical contact with said adjacent electrokinetic material layers, a first column electrode at one end of said column being exposed to said fluid, and a fluid chamber adjacent said first column electrode at said one column end, said chamber being adapted to receive said fluid for contacting with said first column electrode, and a chamber electrode within said fluid chamber, said fluid being positioned between said chamber electrode and said first column electrode comprising the steps:

(a) inputting said fluid into said chamber;
(b) connecting the D.C. voltage source between said chamber electrode and a column electrode creating an electrical field therebetween and drawing charged particles from said fluid into said column;
(c) maintaining said connections for a period of time;
(d) connecting the DC voltage source across a first pair of said column electrodes at said one end, an electrical field being created between said connected column electrodes, charged particles in said intervening electrokinetic material being attracted toward said connected electrodes;
(e) maintaining said connections for a period of time;
(f) unmaking the connections of step (d) as charged particles of interest approach the column electrode of said first pair farthest from said one end of said electrokinetic column;
(g) connecting a second pair of column electrodes to said DC source, said second pair of column electrodes straddling said particles of interest and creating a field having the same polarity as that created by said first pair of column electrodes, said particles of interest being attracted to the column electrode of said second pair farthest from said one end.

4 more elements

Dependencies are inferred from the claim text.

Commercial separation system and method using electrokinetic techniques

Life of this patent

Commercial separation system and method using electrokinetic techniques

Life of this patent

Abstract

Claims36