METHODS AND APPARATUS FOR ATTACHING A FLOW GUIDE TO A STEAM TURBINE FOR RETROFIT OF LONGER ROTATIONAL BLADES

摘要

56,038 Improved methods and apparatus for retrofitting longer last row rotational blade assemblies in steam turbines are disclosed. The apparatus of the present invention permits the exhaust flow guide to be mounted directly to modified last row stationary turbine blades. In a preferred embodiment, the outer blade ring of the last row of stationary blades in a steam turbine is modified by machining two grooves which permit a modified blade assembly outer ring and integral blade ring extension to be mounted in the turbine. The extension section is configured to accept connecting means, such as bolts, which permit the direct attachment of an exhaust flow guide to the modified outer blade ring at each end of the turbine. The present invention simplifies the attachment of such flow guides and can improve the harmonic characteristics of the turbine by lowering the natural frequency of the assembly and include the mass of the flow guide in the mass of the stationary blade assemblies. Methods of modifying steam turbines to add longer last row blades are also disclosed.