Short-circuit ring brazing
Power generation and distribution giant ABB recently installed the largest single-shot short-circuit ring brazing system yet developed by EFD Induction.
Stefano Chieregato of ABB (r.), together with Alessandro Mariani of EFD Induction Italy.
The system, which was installed at the ABB plant in Vittuone outside Milan, Italy, can braze rings with a diameter up to 1,500 mm.
“This system is a milestone,” says Alessandro Mariani of EFD Induction Italy. “Our previous record for a one-shot short-circuit ring brazing system was 1,200 mm, so the system developed for ABB represents quite an increase. And of course, to be selected by such a demanding customer as ABB is always encouraging.”The system comprises customized coils, an EFD Induction Sinac 250/320 power source, and a mounting table. The system’s first project was to braze a 1,500 mm diameter short-circuit-ring for a wind tunnel motor. “The end user,” says Mariani, “is one of the world’s most famous sports car manufacturers, which further testifies to our ability to meet the most stringent quality demands.”
According to Stefano Chieregato of ABB, he and his colleagues examined proposals from six companies before opting for the EFD Induction solution. “There were several reasons behind our choice of EFD Induction for this critical piece of equipment. First, their proposal made technical and economic sense. Second, the company has deep expertise in the field. And third, ABB in Italy has had positive experiences with EFD Induction heating solutions for other applications.”
EFD Induction is one of the world’s leading suppliers of induction-based short-circuit ring brazing systems. “That’s right,” says Mariani. “We have even devised a specialized induction coil that equalizes the temperature around the ring. This coil minimizes energy input into laminations, thereby protecting the shaft from heat and preserving the ring’s integrity.”
Induction brazing to world-class standards: an ABB technician using the EFD Induction system to heat a short-circuit ring.
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