| 摘要 |
The drain gully or catch-pit (2) has a conventional grating cover and frame (3). A perforated basket (1) is suspended on chains from a ring (4) resting in the frame rebate, in the case of a round grating. The ring also includes a sloping collar (6) to prevent run-off from bypassing the basket. A domed rigid net cover (7) fitted on the basket deflects stones or gravel to fall outside the basket into the catch pit. A fabric filter bag is placed in the basket (1) to collect sand, silt, small pollution particles and oil, which would otherwise cause eventual drain blockages. Sudden storm water flows can overflow round the top of the basket (8). |
