Author(s): Yu-Chao Hsu; Chih-Yuan Yang; Chyan-Deng Jan
Linked Author(s):
Keywords: Vortex chamber; Sediment removal efficiency; Vortex flow; Water intake ratio
Abstract: For irrigation and public water uses, to remove sediment (especially fine sediment) from raw river water is one of the most important issues faced today. Some methods have been used to solve this problem, among them the vortex-chamber-type (VCT) sediment extractor has recently been used for extracting sediment by its vortex flow. It has been proved that the VCT device can efficiently remove sediment having a diameter larger than 0. 1 mm. A new design device named as a deep-depth vortex chamber type (DDVCT) sediment extractor is introduced in this study for removing fine sediment. The vortex chamber used in this study has a height of 130 cm, an internal diameter of 48. 0 cm, an inlet pipe diameter of3. 0cm, a circular orifice at the bottom, and an overflow weir at the distance of 95. 0 cm above the bottom orifice. The effects of the bottom orifice diameter, inflow sediment size and concentration on sediment removal efficiency are studied through a series of laboratory experiments by using the DDVCT sediment extractor. Three kinds of bottom orifice having diameters of 0. 5, 0. 7 and 1. 0 cm were used in this study. Four different inflow sediment concentrations were used in experiments, i. e., 22, 42, 62 and 82 g/L, respectively. Two kinds of sediment having median diameter (d50) of 4. 1×10-2 and 3. 7×10-3 mm were employed in experiments. Experimental results show that the sediment removal efficiency for the case of bottom orifice of 0. 5 cm in diameter is frombetter than that of 1. 0 cm in diameter. According to the experimental results, the sediment removal efficiency for the case of large inflow sediment concentration is larger than that of smallinflow sediment concentration. The experimental results also indicate that the DDVCT sediment extractor can efficiently remove fine sediment (d50>2. 0×10-2mm) from sediment-water mixtures.
Year: 2013