Modern Manufacturing Of Advanced Impeller And Diffuser Vane Profiles

Abstract

Both fluid dynamics and manufacturing technology have seen rapid progress over the last few years. Vane profiles need no longer be developed in cavitation demonstration experiments, but can be optimized by computerized numeric simulation, Five-axis milling machines and four-axis electric-discharge machining tools permit manufacturing of the most complicated contours. These modern manufacturing techniques make it possible to work boiler feed pump impellers and diffusers out of a single forging block, complete with front shroud. The manufacturing process begins with numeric simulation and profile optimization directly on the screen; the hydraulic engineer then transmits the 3D data online to the manufacturing engineer; and the vane channel is divided into several segments so that the impeller/diffuser can be manufactured from the solid blank. The hydraulic, manufacturing and materials development steps made over the last few years are outlined herein.