Draft tube structure for hydraulic turbines

摘要

217,313. Taylor, H. B. March 13, 1923. Working-fluid supply.-An existing draft tube which deflects the discharge of a hydraulic turbine from the axial direction but in a non- annular form is adapted to give an annular form to the water passage for at least a portion of its length as described in Specifications 123,132, 137,498, 139,414, 140,004, 154,894, 161,569 and 170,926, by the addition of a central core of metal or concrete. The core may be conical or of a helical form as shown at 45 in Fig. 8. Fig. 13 shows a draft tube wherein the annular passage formed by the core 67 is of varying crosssection the wall 69 being circular but with its axis downstream relatively to the axis of the core. The draft tube wall 661 merges into the outlet wall 73 but the wall 66 is at an angle to the wall 69. The core, if of concrete, may be reinforced and is bonded to the base of the water channel. Reference has been directed by the Comptroller to Specifications 123,132, 137,498, 139,414, 140,004, 154,894, 161,569, and 170,926.