# US 6,413,409 B1 · Flow-through capacitor and method of treating liquids with it > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,413,409 B1 - Document ID: US6413409B1 - Status: Granted - Kind: B1 - Application number: 09/763,008 - Filed: 2001-02-13 - Granted: 2002-07-02 - Earliest claimed: 1998-09-08 - Assignees: Biosource, Inc. - Inventors: Toshiro Otowa; Naoto Tanaka - Web page: https://patentgrep.com/patent/US6413409B1 ## CPC - C02F 1/008: {Control or steering systems not provided for elsewhere in subclass C02F} - C02F 1/46104: {Devices therefor; Their operating or servicing} - C02F 1/46114: {Electrodes in particulate form or with conductive and/or non conductive particles between them} - C02F 1/4691: {Capacitive deionisation} - C02F 1/002: {using small portable filters for producing potable water, e.g. personal travel or emergency equipment, survival kits, combat gear (C02F1/003 takes precedence)} - C02F 1/004: {using large scale industrial sized filters} - C02F 1/283: {using coal, charred products, or inorganic mixtures containing them} - C02F 1/441: {by reverse osmosis} - C02F 1/442: {by nanofiltration} - C02F 2001/46138: {Electrodes comprising a substrate and a coating} - C02F 2201/4611: Fluid flow - C02F 2201/46115: Electrolytic cell with membranes or diaphragms - C02F 2201/4615: Time - C02F 2209/05: Conductivity or salinity - C02F 2303/16: Regeneration of sorbents, filters - C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes) ## Abstract A separator (1), electrode (2) and collector (3), each made of a polygonal sheet, are stacked up in a multi-layer serial arrangement of [{fraction (3/2)}/½] sub n/3, with the provision of a through-hole in the respective sheets in the corresponding position for passage of a liquid. The stack is accommodated in a housing (8) so that it may be compressed from both sides at a pressure 0.5 kg per cubic meter G by tightening a retainer (4) which doubles as a cover. The liquid to be treated is passed through the capacitor through an inlet and outlet (5). ## Claims ### Claim 1 A flow through capacitor essentially comprising a separator, an electrode disposed on either side thereof, and a collector disposed externally of said electrode, characterized in that each of the separator, electrode and collector is an independent or folded flat sheet having a polygonal configuration, that said separator, electrode, and collector are disposed in a multi-layer serial arrangement of [3/2/1/2]n/3 where n is not less than 20, that each of said separator, electrode, and collector comprises a polygonal sheet provided with one or a plurality of through-holes for passage of a liquid in such a manner that when those sheets are assembled into a stack, the corresponding through-holes are aligned to form one or more internal flow passageways, and that the stack of sheets for said separator, electrode, and collector is retained in the condition compressed from both sides at a pressure of not less than 0.2 kg/cm2 G. ### Claim 2 (depends on 1) The flow through capacitor of claim 1 wherein each separator sheet is somewhat larger than the electrode sheet and each collector sheet is larger than said electrode sheet with its extension over the electrode being available for bundling. ### Claim 3 (depends on 1) The flow-through capacitor of claim 1 wherein the separator is an electrically-insulating sheet having a thickness of about 0.01 to 0.5 mm per layer. ### Claim 4 (depends on 1) The flow-through capacitor of claim 1 wherein the electrode comprises an active carbon layer with a surface area of not less than 1000 m2/g. ### Claim 5 (depends on 1) The flow-through capacitor of claim 1 wherein the electrode comprises a molded perforated sheet of carbon with a binder. ### Claim 6 (depends on 1) The flow-though capacitor of claim 1 which includes a central through-hole orifice from which liquid flows. ### Claim 7 (depends on 1) The flow-through capacitor of claim 1 wherein the collector extends out beyond the other sheets and is provided with a through-hole h in the extension. ### Claim 8 (depends on 1) The flow-through capacitor of claim 1 wherein n is up to about 500. ### Claim 9 (depends on 1) The flow-through capacitor of claim 1 wherein the stack pressure is generally 0.2˜10 kg/cm2 G. ### Claim 10 (depends on 1) The flow-through capacitor of claim 1 which includes a housing for the capacitor, a retaining plate, and a means to compress the retaining plate. ### Claim 11 (depends on 1) The flow-through capacitor of claim 1 which includes a means to apply constant DC voltage or current to the collectors and a means to short-circuit between the collectors. ### Claim 12 (depends on 1) The flow-through capacitor of claim 1 which includes a means to switch the polarity of connections. ### Claim 13 (depends on 1) The flow-through capacitor of claim 1 which includes a means to reverse the direction of liquid flow. ### Claim 14 (depends on 1) The flow-though capacitor of claim 1 which includes a means to maintain the voltage of the capacitor without the introduction of a liquid. ### Claim 15 A method of treating a liquid using a flow-through capacitor essentially comprising a separator, an electrode disposed on either side thereof, and a collector disposed externally of said electrode and satisfying all of the following requirements: a) providing that each of the separator, electrode, and collector is an independant or folded flat sheet having a polygonal configuration; b) providing that said separator, electrode, and collector are disposed in a multi-layer serial arrangement of [3/2/1/2]n/3, where n is not less than 20; c) providing that each of said separator, electrode, and collector comprises a polygonal sheet provided with one or a plurality of through-holes for passage of a liquid in such a manner that when those sheets are assembled into a stack, the corresponding through-holes are aligned to form one or more internal flow passageways; and d) passing an ionic substance-containing liquid through said flow-through capacitor and subjecting the liquid to a combination of application of a DC constant voltage or a DC constant current to collectors and either short-circuiting between collectors or constant current discharge or a suitable combination of said application of said voltage or current, said short-circuiting or constant discharge, and reverse connection. ### Claim 16 (depends on 15) The method of treating a liquid according to claim 15 wherein the direction of passage of the liquid is reversed according to a predetermined program. ### Claim 17 (depends on 15) The method of treating a liquid according to claim 15 wherein, when not used or in its preparation stage, the flow-through capacitor is not loaded with the liquid, but kept loaded with a voltage. ### Claim 18 (depends on 15) The method of claim 15 which includes compressing the stacked sheets employing a moveable retaining plate with the capacitor located within a housing. ### Claim 19 (depends on 15) The method of claim 15 providing stacking pressure that the stack of sheets for said separator, electrode, and collector electrode is retained in the condition compressed from both sides at a pressure of not less than 0.2 kg/cm2 G.