Method and apparatus for dielectrophoretically enhanced particle collection
OwnerDavid H. Malcolminventor
Life of this patent
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Abstract
Method and apparatus for the removal of particulate matter, fumes, mists and noxious gases from a gas stream utilizing selectively sized and electrically charged water droplets, preferably between 30 and 60 microns, that exhibit significantly enhanced affinity for smaller uncharged particles through dielectrophoretic attraction, said droplets being present in such relatively low concentration that performance is not limited by space charge. The charged droplets are caused to move relative to the gas stream by inertial or electrostatic means, or both, at such a velocity and path as to maximize encounters between charged droplets and the particles to be collected.
Claims15
In the dielectrophoretically enhanced separation of small sized particles from a moving stream of gas, the steps of
- introducing a spray of discrete liquid droplets of 60 microns or less in diameter and having an electrical charge thereon greater than 10.sup.-3 coulombs per kilogram but not greater than 25 percent of the Rayleigh limit thereon, into said moving gas stream,
- selectively directing the locus of introduction of said spray of liquid droplets in a path relative to the path of advance of said gas stream to maximize geometric interdiction of said charged droplets and the entrained particles in said gas stream,
- and regulating the volume of liquid so introduced to be in the order of about one ten thousandth that of the volume of gas being treated per unit time to minimize space charge degradation of the collecting environment with attendant minimization of dielectrophoretic attraction forces therewithin.
Apparatus for effecting dielectrophoretically enhanced separation of small sized particulates from a moving gas stream comprising
- conduit means for confining said moving gas stream bearing said particles,
- means for introducing a spray of selectively sized and charged liquid droplets into said gas stream in a path relative to the advance of said gas stream to maximize geometric interdiction of said charged droplets and the entrained particles in said gas stream,
- means associated with said spray introduction means for limiting the size of said introduced liquid droplets to 60 microns or less in diameter,
- means for applying an electrical charge of greater than 10.sup.-3 coulombs per kilogram to said emitted spray droplets, such charge not being greater than 25 percent of the Rayleigh limit therefore,
- said means for regulating the volume of liquid so introduced in droplet form to be in the order of about one ten thousandth that of the volume of gas being treated per unit time to minimize space charge degradation of the collecting environment with attendant minimization of dielectrophoretic attraction forces therewithin.
Dependencies are inferred from the claim text.