Main fan

A fan wheel is shrunk onto the main shaft to cool the generator winding. As a welded unit, the main fan must be able to withstand the highest mechanical loads in nominal operation and during short-term overspeeds.

Specification

• Diameter 1500 mm
• Nominal speed 3,500 rpm
• Spin up to 4,700 rpm, PT tested
• 1-flow, duct width 60 – 90 mm
• High-strength tempered steel 1.4313, hardened and tempered to Rm > 940 Pa
• Base material US tested, chemical analysis, strength tested
• TIG welding process (141), welded with semi-automatic machine
• Butt weld, root grinding and PT tested, 8-10 layers
• Filler metal Boehler CN 13/4 IG, shielding gas argon I1
• Preheating temperature 120 – 150 °C
• Weld seam quality according to ISO5817-B
• RT-, MT- tested before and after heat treatment
• Stress-relieved annealing
• Tensile and notched bar impact test of B-sample
• Balanced VDI2060 Quality Q2.5
• Weight 550 kg