APPARATUS AND METHOD FOR IMPROVING FILM ENTRAPMENT OF A MOISTURE PRE-SEPARATOR FOR A STEAM TURBINE

摘要

A moisture pre-separator for a steam turbine includes an inner cylinder, an outer cylinder and a bottom interconnecting lower ends of the inner and outer cylinders. An annular collection chamber formed by the outer surface of the inner cylinder and the inner surface of the outer cylinder and the bottom is vented to communicate steam from the collection chamber to the interior of the inner cylinder, thereby equalizing pressure around the circumference of the entry gap and increasing effectiveness of moisture entrapment. Vanes are provided either on the outer surface of the inner cylinder or the inner surface of the outer cylinder, or both, in order to enhance swirling flow of moisture within the chamber, thereby helping to keep moisture away from the outer surface of the inner cylinder.