公开(公告)号：US3549012A

公开(公告)日：1970-12-22

申请号：US3549012D

申请日：1968-01-03

Applicant: CESKOSLOVENSKA AKADEMIE VED

Inventor： MACKRLE VLADIMIR ,  MACKRLE SVATOPLUK ,  DRACKA OLDRICH

IPC: B01D21/00 ,  B01D24/46 ,  B01D24/48 ,  B01D23/24

CPC classification number: B01D21/0012 ,  B01D21/02 ,  B01D21/2444 ,  B01D24/14 ,  B01D24/4631 ,  B01D2201/206

Abstract: 1,181,051. Filter bed back-washing. CESKOSLOVENSKA AKADEMIE VED. 1 Jan., 1968 [7 Jan., 1967; 5 Dec., 1967], No. 13/68. Heading BID. A filter bed F is backwashed automatically when the level of unfiltered water rises sufficiently for level monitor 13 to close filtrate outlet valve 12, whereupon siphon S 2 starts and produces suction which acts through tube 6 to start siphon S 1 , whereafter unfiltered water flows from tank 10, upwards through bed F and to waste through siphon S 2 , expanding the bed. Monitor 13 also starts a timer 9, which subsequently admits air to both siphons by opening valve 7 and stops the backwashing, opens valve 4 to discharge the first filtrate following backwashing to waste and finally closes valve 4 and opens valve 12. Tank 10 acts as a preliminary purifying stage by virtue of a sludge blanket B therein, through which water flows upwards.