# US 8,784,657 B2 · Plasma discharge self-cleaning filtration system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,784,657 B2 - Document ID: US8784657B2 - Status: Granted - Kind: B2 - Application number: 12/672,005 - Filed: 2008-08-07 - Published: 2011-11-03 - Granted: 2014-07-22 - Earliest claimed: 2007-08-07 - Assignees: Drexel University - Applicants: Young I. Cho; Alexander Fridman; Alexander F. Gutsol; Yong Yang - Inventors: Young I. Cho; Alexander Fridman; Alexander F. Gutsol; Yong Yang - Web page: https://patentgrep.com/patent/US8784657B2 ## CPC - B01D 35/06: Filters making use of electricity or magnetism (ultrafiltration, microfiltration B01D61/14; electrodialysis, electro-osmosis B01D61/42; devices comprising filters and magnetic separators B03C1/30) - B01D 29/62: Regenerating the filter material in the filter (devices for taking out of action one or more units of multi-unit filters, e.g. for regeneration, B01D35/12) - B01D 29/72: involving vibrations - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) ## Abstract The present invention is directed to a novel method for cleaning a filter surface using a plasma discharge self-cleaning filtration system. The method involves utilizing plasma discharges to induce short electric pulses of nanoseconds duration at high voltages. These electrical pulses generate strong Shockwaves that disintegrate and dislodge particulate matter located on the surface of the filter. ## Claims ### Claim 1 A method of cleaning a filter having filtered particulate thereon, said filter positioned within a liquid, said method comprising: applying an electric potential to a first electrode positioned within the liquid, so as to generate a pulsed plasma discharge said pulsed plasma discharge creating an electrical pulse vaporizing at least a portion of the liquid to cause a shockwave within the liquid, wherein the shockwave travels to the filter to impart a force upon the filter; said force disintegrating or dislodging the filtered particulate. ### Claim 2 (depends on 1) The method of claim 1, wherein the electrical potential is applied for a duration of 1 to 500 nanoseconds. ### Claim 3 (depends on 2) The method of claim 2, wherein the electrical potential is applied for a duration of 10 to 200 nanoseconds. ### Claim 4 (depends on 3) The method of claim 3, wherein the electrical potential is applied for a duration of 50 to 150 nanoseconds. ### Claim 5 (depends on 1) The method of claim 1, wherein the electrical potential is within a voltage range of about 10 kV to 40 kV. ### Claim 6 (depends on 5) The method of claim 5, wherein the electrical potential is within a voltage range of about 30 kV to 40 kV. ### Claim 7 (depends on 1) The method of claim 1, wherein a frequency of the electrical potential is in the range of approximately 0.1 Hz to 500 Hz. ### Claim 8 (depends on 7) The method of claim 7, wherein the frequency of the electrical potential is in the range of approximately 1 Hz to 100 Hz. ### Claim 9 (depends on 1) The method of claim 1, wherein the electrode is stainless steel. ### Claim 10 (depends on 1) The method of claim 1, wherein the electrical potential is applied to a plurality of second electrodes. ### Claim 11 (depends on 1) The method of claim 1, wherein the filter is a metal, a carbon-containing material, or a non-metallic medium. ### Claim 12 (depends on 11) The method of claim 11, wherein the filter is stainless steel. ### Claim 13 (depends on 11) The method of claim 11, wherein the filter comprise a ceramic. ### Claim 14 (depends on 13) The method of claim 13, wherein the filter further comprises a metallic coating. ### Claim 15 A self-cleaning filter apparatus comprising: a chamber containing liquid, said chamber having a defined volume; a liquid inlet for inletting unfiltered liquid into the chamber, wherein the unfiltered liquid comprises particulate; a filter mesh for filtering at least a portion of the particulate in the unfiltered liquid to convert the unfiltered liquid into filtered liquid; and a first electrode positioned in the volume within the liquid, located proximate to the filter mesh; said electrode in electrical communication with a power supply, wherein the power supply is configured to cause a suitable electrical potential to form a pulsed plasma discharge at the electrode, thereby vaporizing at least a portion of the liquid, causing a shockwave within the liquid, wherein the shockwave travels to the filter to impart a force upon the filter; said force disintegrating or dislodging the filtered particulate. ### Claim 16 (depends on 15) The apparatus of claim 15, wherein the plasma discharge is a corona discharge plasma or a spark discharge plasma. ### Claim 17 (depends on 16) The apparatus of claim 16, wherein the plasma discharge is controlled by the distance between two electrodes in a spark gap, wherein the spark gap is configured to act as a fast high current switch. ### Claim 18 (depends on 15) The apparatus of claim 15, wherein the chamber is a cartridge filter. ### Claim 19 (depends on 15) The apparatus of claim 15, wherein the chamber is a sand filtration system. ### Claim 20 (depends on 15) The apparatus of claim 15, further comprising a first outlet for the filtered liquid and a second outlet for the particulate. ### Claim 21 A system, comprising: a first filter chamber containing liquid, said chamber having a defined volume; a first filter positioned within the liquid of the first filter chamber; at least one first electrode positioned within the liquid of the first filter chamber at a location proximate to the first filter; and a power supply in electrical communication with the at least one first electrode, wherein the power supply is configured to provide an electrical potential to the at least one first electrode sufficient to generate pulsed plasma discharge, the plasma discharge being sufficient to create an electrical pulse from the plasma discharge within the liquid which vaporizes at least a portion of the liquid to cause a shockwave within the liquid, wherein the shockwave travels to the first filter to impart a force upon the at least one first filter and disintegrate or dislodge a filtered particulate on the first filter. ### Claim 22 (depends on 21) The system of claim 21, wherein the filter chamber comprises an inlet to allow unfiltered liquid into the defined volume, a first outlet to allow at least filtered liquid to exit the defined volume, and a second outlet to allow at least the filtered particulate to exit the defined volume. ### Claim 23 (depends on 21) The system of claim 21, wherein the chamber is a cartridge filter. ### Claim 24 (depends on 21) The system of claim 21, wherein the chamber is a sand filtration system. ### Claim 25 (depends on 21) The system of claim 21, further comprising: a second filter chamber containing liquid, said chamber having a second defined volume; a second filter positioned within the liquid of the second filter chamber; and at least one second electrode positioned within the liquid of the second filter chamber at a location proximate to the second filter, wherein the power supply is in electrical communication with the second electrode.