Vortex‐Tube Sediment Extractors. II: Design

Abstract

The vortex tube is a device for extracting sediment from canals. A companion paper presented methods for assessing the trapping efficiency of vortex tubes. This present paper provides a flow analysis that is based on flow continuity, a momentum balance along the tube axis, and an angular momentum balance as flow enters the tube. The predictions of the analysis are compared with laboratory and field data: the ratio of an observed discharge coefficient to its predicted value had a mean value of 0.97 and a standard deviation of 0.11 over 956 measurements. The analysis is then used to form design guidelines so that the following three criteria are satisfied: the difference in head between the canal and the vortex tube outlet is acceptable; the tube does not block with sediment; and water is near uniformly abstracted along the length of the tube. Finally, a procedure is given for the design of vortex tubes that uses as input the required trapping efficiency, the required head loss, and the canal characteristics.