WATER-DROP CAPTURING APPARATUS FOR STEAM TURBINE

PURPOSE:To enhance water-drop extracting efficiency of a steam turbine, by providing a water- drop capturing chamber and a tongue-like water-drop capturing piece in the lower face portion of a stator blade on the side of the leading edge thereof, in the manner that they oppose each other at a proper interval. CONSTITUTION:Water-drop flow near the diaphragm wall 21 of a stator blade 23 is strong in the direction of its radial component as shown by arrows 32 in the drawing, so that it constitutes an upward flow toward the corner portion of the lower face of the stator blade and the inner surface of the diaphragm wall 21 and is accumulated on the wall surface as robbon-like thin film flow. At the same time, water thus accumulated flows downward inside the blade. Here, film flow of water on the lower surface of the stator blade along the length of the same at the final stage of a low- pressure turbine presents extremely complicated behavior since it is influenced by various factors such as pressure distribution on the blade surface, shear flow by main steam flow, profile of the blade, etc. Further, thick film flow of water is concentrated at a position near the leading edge, but at the downstream region, thickness of the water film is decreased and water film is flowed away toward a rotor blade 24. In consideration of the above, water-drop extracting efficiency is enhanced by providing a tongue-drop water-drop capturing piece 39 and a water-drop capturing chamber 45.