# US 2014/0190908 A1 · Continuous circulation sand filter and continuous circulation sand filtering method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0190908 A1 - Document ID: US20140190908A1 - Status: Published application - Kind: A1 - Application number: 14/240,130 - Filed: 2012-09-06 - Published: 2014-07-10 - Earliest claimed: 2011-09-07 - Assignees: Coway Co., Ltd. - Inventors: Youn-Kook Kim; You-Mee Na; Ho-Chan Jung; Ha-Na Yu - Web page: https://patentgrep.com/patent/US20140190908A1 ## CPC - C02F 1/004: {using large scale industrial sized filters} - B01D 24/22: Downward filtration, the filter material being supported by pervious surfaces - B01D 24/4689: {Displacement of the filtering material to a compartment of the filtering device for regeneration} - 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) - 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 Provided is a continuous circulation sand filter including a filtering barrel filled with a sand filtering layer, an inflow tube for introducing raw water into the filtering barrel, a treated water discharge part for discharging treated water purified by passing the raw water through the sand filtering layer from a lower end of the sand filtering layer to an upper end thereof, an air lift tube for transferring contaminated sand, located in the lower end of the sand filtering layer, from a lower part of the filtering barrel to an upper part thereof, a transfer water discharge filter contacting the air lift tube to discharge transfer water moved upward together with sand through the air lift tube and trap the sand and a foreign substance, a descent guide tube downwardly moving the sand and the foreign substance moved to the upper part of the filtering barrel through the air lift tube, and a foreign substance separation tube suctioning the downwardly moving foreign substance to remove the foreign substance from the downwardly moving sand, and discharging the foreign substance. ## Claims ### Claim 1 A continuous circulation sand filter comprising: a filtering barrel filled with a sand filtering layer; an inflow tube for introducing raw water into the filtering barrel; a treated water discharge part for discharging treated water purified by passing the raw water through the sand filtering layer from a lower end of the sand filtering layer to an upper end thereof; an air lift tube for transferring contaminated sand, located in the lower end of the sand filtering layer, from a lower part of the filtering barrel to an upper part thereof; a transfer water discharge filter contacting the air lift tube to discharge transfer water moved upward together with sand through the air lift tube and trap the sand and a foreign substance; a descent guide tube downwardly moving the sand and the foreign substance moved to the upper part of the filtering barrel through the air lift tube; and a foreign substance separation tube suctioning the downwardly moving foreign substance to remove the foreign substance from the downwardly moving sand, and discharging the foreign substance. ### Claim 2 (depends on 1) The continuous circulation sand filter according to claim 1, wherein the transfer water discharge filter comprises a mesh formed of a metal. ### Claim 3 (depends on 1) The continuous circulation sand filter according to claim 1, wherein a suction pump is disposed on the foreign substance separation tube to forcibly discharge a foreign substance. ### Claim 4 (depends on 1) The continuous circulation sand filter according to claim 1, wherein the transfer water discharge filter is disposed on an upper end of the air lift tube such that transfer water passes through the transfer water discharge filter. ### Claim 5 (depends on 1) The continuous circulation sand filter according to claim 1, further comprising an air inflow tube compressing air to supply the compressed air to a lower end of the air lift tube, wherein upward moving force of the compressed air upwardly moves the contaminated sand within the air lift tube. ### Claim 6 A continuous circulation sand filtering method comprising: supplying raw water to a sand filtering layer and moving the raw water to an upper part of the sand filtering layer to filter the raw water, thereby producing treated water; upwardly moving contaminated sand and transfer water by using upwardly moving air, so as to separate the contaminated sand and the transfer water into a foreign substance, sand, and the transfer water; separating the foreign substance, the sand, and the transfer water into the transfer water, as a liquid, and the sand and the foreign substance as solids; discharging the transfer water together with the treated water; and separating the sand and the foreign substance from each other. ### Claim 7 (depends on 6) The continuous circulation sand filtering method according to claim 6, wherein a filter is used to separate the foreign substance, the sand, and the transfer water into the liquid and the solids. ### Claim 8 (depends on 6) The continuous circulation sand filtering method according to claim 6, wherein in the separating of the sand and the foreign substance, the sand and the foreign substance are moved downward. ### Claim 9 (depends on 8) The continuous circulation sand filtering method according to claim 8, wherein the foreign substance separated by downwardly moving the sand and the foreign substance is discharged through suction. ### Claim 10 (depends on 8) The continuous circulation sand filtering method according to claim 8, wherein a descent guide tube and a foreign substance separation tube obliquely diverging upward from a side surface of a lower end of the descent guide tube are used to separate the sand and the foreign substance.