| 摘要 |
1,234,089. Filter bed. CKD DUKLA NARODNI PODNIK. 18 Dec., 1968 [19 Dec., 1967; 5 Jan., 1968], No. 60200/68. Heading B1D. In the filtration of a suspension of solid particles in water through granular filter bed 29, 30 wherein filtration flow occurs downwards from the top of the bed and simultaneously upwards from the bottom, filtrate being collected at 54, all of the suspension to be treated is first introduced into a space 28 above the bed. This allows sedimentation of the largest particles and degasing to occur. Chemicals may be added to the suspension in space 28. As described, suspension flows in at 42, over weir 41 and under baffle 55. While some of it flows downwardly through bed layers 29, 30, the remainder passes through non-return valve 36, conduit 34 and nozzle floor 31 to rise up through layer 30. Filtrate is discharged at 46. To clean the filter, tank 41 is drained and scavenging air is admitted at 50, this agitating the bed. Backwash water is then admitted at 52, discharging into tank 41, ball valve 36 preventing bypassing. A closed housing filter is also disclosed, Fig. 1 (not shown). |
