| 摘要 |
1283407 Comminuting sewage; rotary drum filter and screen R N CRANDALL and C H NORDELL 20 Aug 1969 [6 Sept 1968] 41458/ 69 Headings BID B2A and B2H [Also in Division C1] The solids in a flow of sewage are lifted above the liquid level, the soft organic solids being comminuted and returned to the sewage flow, while the uncomminuted solids are conveyed away from the flow. The apparatus comprises a cylindrical screen 15 separating an influent chamber 44 from an effluent chamber 46. The screen 15 is rotated on a shaft 68 by a motor 170 through gears 176, 180 and a chain 178 so that fingers 106 projecting from the screen lift solid material from the influent chamber 44, until a cam surface 114 engages a roller 111 Fig. 9, on the frame 108, 110, Fig. 8 supporting the fingers, causing the frame to pivot about a shaft 104 against the action of a spring 112 retracting the fingers through closely fitting holes 121, Fig. 2, and depositing particles of solid T on the surface of the screen. On further rotation of the drum these particles T lift a gravity biassed plate 18, pivoted at 18c and comprising a metal backing plate 18a bonded to a rubber sheet 18b to flatten, and remove water from such solids as rags &c and to scrape soft material from sheet 18b. The particles T which are then removed from the drum by a skewmounted roller 16 rotated about the shaft 140 in the same direction as the screen 15 but at a faster speed. The roller 16 consists of flexible plates 134, and in another embodiment, may be of a smaller diameter towards the centre, Fig. 7A (not shown). The particles T are removed on a conveyor 20 to an elevator 22. Soft organic material M Fig. 11 (not shown) collects on the outside of the screen 15 and is communicated by the plate 18 which pushes this material into the holes 15a see also Fig. 4c (not shown) in the screen from which it is washed into the screen and effluent chamber 46 by the influent from the chamber 44, there being a difference in levels inside and outside the screen due to the partial blockage of the screen holes. If the screen is completely blocked a weir 52 allows an over-flow of influent directly into the effluent chamber 46. |
