Brazing copper with induction heating
A mobile Minac being used to braze windings. The ‘Twin’ version boasts two independent outputs.

Induction heating: Copper brazing

Two of Europe’s leading power generation technology companies recently placed repeat orders for EFD Induction’s mobile Minac Twin systems. The first, ANDRITZ HYDRO, involves a Minac 25/40 Twin.

The system will be used for copper brazing at ANDRITZ HYDRO’s facility in Linz, Austria. “This latest order means ANDRITZ companies have now purchased about 25 Minac systems from us over the past two decades,” says Matthias Gruber, managing director of EFD Induction Austria. “And that number does not include five Minac systems delivered to ANDRITZ HYDRO in India during the past two years, or the four Minacs delivered to the same customer in Brazil last autumn.”  The Minac is a versatile, mobile induction heating system available with various output powers up to a maximum of 220 kW at intermittent operation. Automatic output matching—which ensures optimal power output for different heating operations, coils and materials— is standard for all Minac models. ‘Twin’ models feature two independent power outputs from a single  converter, in effect offering two heating systems in one. 

“When a company such as ANDRITZ HYDRO, with its stringent standards in a demanding industry, places repeat orders for an equipment item, then you know you’ve passed a tough quality control test,” says Gruber. “It proves just how much value the Minac can add to a company’s operations.”

Positive experience

The other repeat order involves a Minac 18/25  Twin, and came from Jeumont Electric, the France-based specialist in power generation and conversion technologies. The Minac is being employed to wind large  two- and four- pole rotors. Two teams use the Minac to simultaneously braze conductors that are up to eight meters apart from one another.  “The order,” says Olivier Feraud of EFD Induction France, “came about because of Jeumont Electric’s previous positive experience with our Minac systems. So when it came to acquiring another mobile induction heating solution, Jeumont Electric knew who to turn to.” According to Feraud, the Minac Twin’s independent power outputs mean “a single mobile heater weighing less than 80 kilos can perform two completely separate heating operations simultaneously.”

Another factor that makes the Minac popular with companies such as Jeumont Electric is the system’s versatility. “The Minac,” explains Feraud, “can handle a wide range of applications on practically any  electrically conductive material. So the same system can be used to braze, shrink fit, straighten, cure and heat treat.” 

A member of the Altawest Group, Jeumont Electric builds and maintains a wide range of generators and motors (synchronous and asynchronous), control systems and converters. The company is mainly active in the electric power plant, marine and process industries.