MF Generators: Significantly Improving the Rigidity of Pelton Turbines by Induction Annealing

Turbine makers benefit greatly from stress-relieving by induction annealing with eldec MF generators: the technique guarantees highly efficient annealing on Pelton turbines used in hydroelectric power plants.

MF Generators maintain a fast pace in Turbine Production

There are few mechanical parts that have to withstand loads as great as those imposed on the Pelton turbines in hydroelectric power plants: The water first gushes out under high pressure from specially designed nozzles, before hitting the individual blades at high speed. The blade that is “hit” first drives the wheel a short distance, but is then idle again for a revolution – this results in high alternating forces in the root area of the blade.

To prevent fatigue fractures in this area, turbine makers  anneal the weld between the turbine wheel and blade. This “gentle” heating process improves the durability of the part significantly. However, the heating must be carried out with high precision and repeatability to ensure turbine quality requirements are met.

In this context, stress-relieving induction annealing using an MF generator from eldec has proven to be an ideal process. The device allows the heating to be controlled via a practical LED display: Red means the temperature is too high, blue means it is too low, and green is just right. The user also benefits from the speed of the annealing process, which is completed in seconds. As the heat is generated directly in the workpiece by means of an alternating electromagnetic field, the process can be carried out very precisely, quickly, and with high energy conversion efficiency.

• Rapid annealing process
• Precise control
• High repeatability
• Economical energy consumption
• Customized configuration

Relevant Generators

• MICO-M System
• ECO-LINE Generators