Patent ID: 9567241
Date: 2017-02-14
CPC Classifications: B01D,C02F

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.