Conventional Francis Runner manufacturing used to be very tough as most of the metal removal between the buckets had to be done using manual grinders/polishers and it used to take months together for completion and in addition to this the operators had to be properly protected against grinding dust which is mostly responsible for the respiratory diseases. On top of this we had to compromise on the runner efficiency as the complete runner paths could never match with the actual designer’s 3D concepts. Material soundness would also be a very big issue as complicated construction would not allow access to Nondestructive tools. and finally, the CG of the runner would shift as metal removal will not be uniform which will lead to heavy residual balancing issues.
Well, that was the way we used to deal with single cast Francis Runners but now the story is different.
We have the buckets, the skirt and the crown castings separately machined, access to NDT tools is perfect. Runner efficiency is not compromised at all because all inlet and outlet water ways are machined to very fine accuracy and not ground anymore. Since all the parts are machined so CG does not shift much and hence no issues with dynamic balancing. Manufacturing is absolutely environment friendly and here you will find attached pics of many such Francis Runners getting ready for their final destinations in different parts of the world.
FLOVEL name has been synonymous with the hydro power sector for over four decades. FLOVEL is a full-line supplier of electromechanical equipment and services for small and medium size hydro power plants manufacturer of hydraulic turbines, valves and turnkey supplier of electro mechanical packages for hydro power projects and ranks amongst the leading players globally. FLOVEL manufacturers complete range of Pelton, Francis, Kaplan, Axial Flow turbines and Valves for hydropower projects. The strength of FLOVEL is in its ability to offer all-inclusive solutions (Electro Mechanical-Turnkey Packages).