DESIGN OF SEDIMENT EJECTION DEVICES WITH SPECIAL REFERENCE TO SANJAY HYDEL PROJECT

Abstract

Efforts to exclude sediment from the water drawn from streams and rivers, for use in irrigation, hydro-upo wer and domestic purposes$ start at intake structure itself. However, in mo st of the intake structures, it is not entirely possjbla to prevent the entrainment of all undesirable sedi-ments, Therefore, measures to eject such sediments as per requirement, become necessary. In context to the use of water in hydropower plants, the extent of ejection is normally specified in terms of the permissible particle size and concentration of sediments. The limits being severe for high hoad.plants than that for medium and low head plants. Cases of extensive damage, some-times needing replacement of the entire. turbine units within a year or few years of commissioning, have been repor. ted in various parts of the world whenever the permissible limits of sediment size and concentration have not been adhered to...