Author(s): K. H. M. Ali; S. Bassiakos; R. Burrows
Linked Author(s):
Keywords: Sediment traps; Efficiency; Saltation length; Synthetic particles
Abstract: At the present, there is very little guidance regarding the management of in-sewer solids. Very recently (6) a joint study was undertaken in the UK to refine the design and promote the use of small invert sediment traps to localise the deposition of sediments in sewers. Experience suggests that many of the problematic in-sewer sediments arrive by means of bed-load type mechanisms. In combined sewers, sediments are very variable in size and density. The paper describes the laboratory performance of model sediment traps of different lengths subjected to bed particles of different size and specific gravity. Investigations included the measurement of velocity-distributions in the sewer and the sediment trap as well as particle trajectories. Experiments show close correlation between the trap's particle retention efficiency and sediment saltation length. This enables us to design a prototype sediment trap for a given range of flow and sediment characteristics.
Year: 2003