| 摘要 |
A deep bed upflow filter (10) for removing suspended solids from an influent stream to provide a clean filtrate, comprising an upright vessel (12) having a vertical axis (14), top and bottom ends (16, 18) and contiguous upper (20), lower (22), and intermediate (24) regions between the ends. The upper region contains filtrate (26) up to a first elevation (28) and an outlet (30) for drawing the filtrate out of the vessel. The intermediate region contains particulate filter media (32) for removing the suspended solids from influent moving upwardly through the media as the media, dirtied with solids, moves downwardly into the lower region. The lower region is generally tapered (36) inwardly toward the vessel bottom and contains dirty media (34) that has moved downwardly from the intermediate region. Influent is introduced (44) between the intermediate and lower regions, and the dirty media is collected (46) at the bottom and transported (50) to a regenerative washing compartment (52). A portion of the reject flow (64) from the wash compartment is delivered (72, 74) to the dirty media in the lower region of the vessel and another portion (72, 78) is delivered to the area (46, 48, 50) where the dirty media is collected and transported. This latter portion is preferably introduced into a collection conduit (46) through a pipe (130) having a concentric inner tube (140) by which air is injected to fluidize and move the mixture of air, dirty media, and reject water in the conduit (46) toward an airlift (48, 148). |
